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Cold email infrastructure checklist: 25 configuration items to verify before sending a single cold email, from domain registration through authentication, warmup, and monitoring.
Marcus Chen
Outbound sales trainer, 150k+ emails sent · Updated June 23, 2026
Last updated: August 2026 · Marcus Chen, Outbound sales trainer, 150k+ emails sent
TL;DR — 5 things to know before reading
The cold email infrastructure checklist exists because problems in cold email infrastructure do not fail loudly. A campaign launched with missing DMARC does not return an error — it just achieves 40% inbox placement instead of 90% and leaves the sender wondering why reply rates are low. A campaign launched from an unwarmed domain delivers to spam for 60% of recipients without any visible indication in the campaign tool.
The checklist forces the audit before any sends go out. Every item is either clearly done or clearly not done. A check on each item is the difference between a campaign that works from day one and one that spends weeks at low performance before the infrastructure problems are identified and corrected.
This guide presents the full 25-item pre-launch checklist in the order it should be completed, grouped by the infrastructure layer it addresses.
1.1 Sending domain is separate from primary business domain
Sending domain: a domain registered specifically for cold outreach. Primary business domain: the company's public identity domain (website, customer email, marketing).
Never use the primary business domain for cold email. Cold outreach generates spam complaints at a higher rate than legitimate business correspondence, and complaints on the primary domain affect all email sent from that domain.
Tool: domain registrar. Status: verify the sending domain is registered and not the primary business domain.
1.2 Sending domain is at least 2 weeks old before warmup begins
Brand-new domains with no registration history are evaluated with heightened scrutiny by mailbox providers regardless of authentication or warmup status. Register sending domains at least 2 weeks before beginning the warmup period.
Tool: domain registrar registration date. Status: verify domain registration date.
1.3 Domain naming follows the approved pattern
Sending domains should be plausibly associated with the sending organization without being identical to the primary business domain. Naming patterns: companyname-outreach.com, getmeeting-companyname.com, growth-companyname.io.
Random strings (abc123mail.com) or generic names (emailoutreach.co) with no connection to the organization look like spam infrastructure and are evaluated less favorably.
Status: verify domain name follows the pattern.
1.4 Domain count matches volume requirements
Per Woodpecker's guide on daily sending limits, each inbox safely sends 30–50 cold emails per day. At 3 inboxes per domain, each domain supports 90–150 sends per day.
| Monthly contact target | Domains needed |
|---|---|
| Under 5,000/month | 1–2 |
| 5,000–10,000/month | 2–3 |
| 10,000–20,000/month | 3–5 |
| 20,000+/month | 5+ |
Status: verify domain count matches monthly volume target.
1.5 All sending domains added to Google Postmaster Tools
Google Postmaster Tools provides domain reputation monitoring specific to Gmail. Every sending domain must be added to Postmaster Tools before warmup begins so that reputation data begins accumulating from day one.
Tool: postmaster.google.com. Status: verify each domain is verified in Postmaster Tools.
Per the Mailgun SPF, DKIM, and DMARC guide, all three records must pass before warmup begins.
2.1 SPF record configured and passing
SPF (Sender Policy Framework) is a DNS TXT record that authorizes specific mail servers to send from the domain. Test: enter the domain in MXToolbox's SPF checker and verify "SPF Record Found" and "Passed."
Tool: mxtoolbox.com/spf.aspx. Status: PASS required.
2.2 DKIM record configured and passing
DKIM (DomainKeys Identified Mail) is a cryptographic signature added to outgoing email. Test: enter the domain in MXToolbox's DKIM checker and verify the signature is valid.
Tool: mxtoolbox.com/dkim.aspx. Status: PASS required.
2.3 DMARC record configured and passing
DMARC (Domain-based Message Authentication) defines handling for SPF/DKIM failures and blocks domain spoofing. A DMARC record with at minimum p=none must be present. p=quarantine or p=reject is preferred for stronger phishing protection.
Tool: mxtoolbox.com/dmarc.aspx. Status: PASS with policy required.
2.4 Inframail automatic DNS configuration verified
Inframail configures SPF, DKIM, and DMARC automatically during inbox provisioning. After provisioning, verify all three records are passing in MXToolbox before enrolling inboxes in warmup.
Status: verify all three records passing per items 2.1–2.3 above.
2.5 No MX record conflicts
MX records direct incoming email to the correct mail server. Verify that MX records for the sending domain are correctly configured and point to the inbox provider (Microsoft 365 in the case of Inframail).
Tool: mxtoolbox.com/mx.aspx. Status: MX record present and correct.
2.6 Custom tracking domain configured (optional but recommended)
A custom tracking domain for click and open tracking in Instantly ensures tracking links use the sender's own subdomain rather than a shared tracking domain. This prevents shared tracking domain blacklisting from affecting click tracking.
Tool: Instantly workspace settings. Status: configured if tracking is enabled.
3.1 Inbox count matches volume requirements
| Inbox count | Daily capacity | Monthly capacity |
|---|---|---|
| 2 inboxes | 80–100/day | 1,680–2,100/month |
| 6 inboxes | 240–300/day | 5,040–6,300/month |
| 12 inboxes | 480–600/day | 10,080–12,600/month |
| 20 inboxes | 800–1,000/day | 16,800–21,000/month |
Assumes 40–50 emails/inbox/day, 21 working days/month. Source: Woodpecker's guide on daily sending limits — verified June 2026
Status: verify inbox count matches monthly volume target.
3.2 All inboxes connected to Instantly
All sending inboxes must be connected to Instantly before warmup begins. Connection is via SMTP/IMAP credentials or OAuth depending on the inbox provider.
Tool: Instantly workspace → Inboxes. Status: all inboxes show as connected.
3.3 Sending limits configured per inbox
Configure per-inbox daily sending limits in Instantly to prevent over-sending above the safe ceiling. Set to 40–50 per inbox per day for fully warmed inboxes. During soft launch (weeks 4–6), set to 20–30 per inbox per day.
Tool: Instantly inbox settings. Status: limits configured.
3.4 Inbox rotation configured
Instantly's inbox rotation distributes sends across all connected inboxes automatically. Verify that rotation is enabled and that the correct inbox pool is assigned to each campaign (particularly important for agency setups with per-client inbox pools).
Tool: Instantly campaign settings. Status: rotation enabled for correct inbox pool.
4.1 All inboxes enrolled in Instantly warmup network
Every new inbox must be enrolled in Instantly's warmup network from day one. Warmup runs automatically once enrolled. Per Woodpecker's email warmup guide, the minimum warmup period before cold sends is 4 weeks.
Tool: Instantly warmup settings. Status: all inboxes enrolled, warmup running.
4.2 Warmup timeline tracked per inbox
Track the warmup start date for each inbox. Cold campaign sends are not launched until each inbox has completed the minimum 4–6 week warmup period.
Status: warmup start dates documented, launch date 4–6 weeks after start.
4.3 Warmup runs concurrently with campaigns (ongoing)
Warmup should not stop when cold campaigns begin. Ongoing warmup provides continuous positive engagement signals that offset cold email's natural negative signals. Verify warmup remains active for all inboxes throughout the campaign lifecycle.
Tool: Instantly warmup settings. Status: warmup running alongside active campaigns.
5.1 Contact list is verified
Unverified contact lists generate hard bounce rates that damage domain reputation. Bounce rate must stay below 2% per campaign. Per Woodpecker's 2025 cold email benchmark study, top-quartile senders achieve 15–20% reply rates partly because their contact lists generate near-zero bounces.
Quarvio delivers pre-verified B2B contacts that eliminate bounce rate as a deliverability risk.
Status: contact list is verified or sourced from a verified provider.
5.2 Contact list has ICP filter applied
Cold email to wrong-fit contacts generates high spam complaint rates (recipients who have no reason to want the email mark it as spam). Apply ICP filters (industry, company size, job title, region) before uploading contacts to Instantly.
Status: contact list filtered to ICP before import.
5.3 Contact list loaded into correct Instantly campaign
Verify contacts are uploaded to the correct campaign, not to another client's campaign or a different segment. For agencies with multiple client sub-accounts, verify the upload target before confirming.
Tool: Instantly leads import. Status: contacts in correct campaign.
5.4 Global suppression list populated and applied
Opted-out contacts from previous campaigns must be on the global suppression list before any new campaigns launch. Instantly's suppression list feature prevents opted-out contacts from receiving new sends across all campaigns.
Tool: Instantly suppression list. Status: suppression list current and applied to all campaigns.
5.5 Unsubscribe mechanism included in all sequences
CAN-SPAM requires a clear opt-out mechanism in every commercial email. Include an unsubscribe line in every sequence email. Instantly can automate opt-out handling when the opt-out response is detected.
Status: opt-out line present in every sequence email.
6.1 Google Postmaster Tools monitoring schedule set
Weekly review of Google Postmaster Tools for all active sending domains. Any domain showing below High reputation requires immediate investigation.
Tool: postmaster.google.com. Status: monitoring schedule documented, Postmaster showing data.
6.2 MXToolbox blacklist monitoring schedule set
Monthly check of all sending domains against the MXToolbox blacklist checker. Any domain appearing on a major blacklist (Spamhaus, Barracuda) requires immediate investigation and removal.
Tool: mxtoolbox.com/blacklists.aspx. Status: monthly check scheduled.
| Section | Items | Tool |
|---|---|---|
| Domains | 5 items | Domain registrar, Google Postmaster Tools |
| Authentication | 6 items | Inframail (auto), MXToolbox |
| Inbox setup | 4 items | Inframail, Instantly |
| Warmup | 3 items | Instantly warmup network |
| Contact data | 3 items | Quarvio, Instantly |
| Compliance | 2 items | Instantly suppression list |
| Monitoring | 2 items | Google Postmaster Tools, MXToolbox |
| Total | 25 items |
"The checklist concept sounds obvious until you realize how many items most teams skip. We audited our original setup against a version of this list and found seven items incomplete: no DMARC policy, warmup had been turned off six weeks in, suppression list was not being applied to new campaigns, and Postmaster Tools had not been checked in two months. Four of the seven were recoverable immediately. The other three (DMARC configuration and the warmup gap) had been causing deliverability degradation we had been attributing to copy for three months. The full setup, done once correctly, is not that complicated. It is the audit against a complete list that matters." — G2 reviewer, Instantly reviews on G2
Instantly holds a 4.9/5 rating from 2,800+ verified reviews on G2, with warmup automation, inbox rotation, and suppression list management cited as the checklist items that Instantly handles automatically, reducing the manual configuration surface for cold email operations.
The 25-item checklist covers seven layers of infrastructure. The following reference provides the specific tool actions, verification steps, and settings for each layer.
| Item | Tool | Action | Verification |
|---|---|---|---|
| 1.1 Separate sending domain | Domain registrar | Register [brand]-outreach.com or get[brand].com | Domain WHOIS shows registration separate from primary |
| 1.2 Domain age 2+ weeks | Domain registrar | Register domain at least 14 days before warmup starts | Registration date in WHOIS |
| 1.3 Domain naming convention | — | Use brand-associated name pattern | Review manually |
| 1.4 Domain count per volume | Domain registrar | Register 1 domain per 2,500–3,000 contacts/month | Count vs. monthly contact target |
| 1.5 Postmaster Tools enrollment | postmaster.google.com | Add domain, complete TXT record verification | Domain shows as verified in Postmaster |
All three authentication records are configured automatically by Inframail. Verify each passes in MXToolbox after provisioning before enrolling in warmup.
| Record | MXToolbox checker URL | Expected result |
|---|---|---|
| SPF | mxtoolbox.com/spf.aspx | SPF Record Found + Passed |
| DKIM | mxtoolbox.com/dkim.aspx | Valid DKIM signature found |
| DMARC | mxtoolbox.com/dmarc.aspx | Record found + policy set |
| MX records | mxtoolbox.com/mx.aspx | Points to Microsoft 365 mail servers |
| Blacklist | mxtoolbox.com/blacklists.aspx | Zero listings on all major lists |
| Item | Instantly setting location | Value |
|---|---|---|
| 3.1 Inbox count | Inframail + Instantly workspace | 3 inboxes per domain minimum |
| 3.2 Inbox connection | Instantly → Inboxes → Add inbox | All inboxes show Connected status |
| 3.3 Daily sending limit | Instantly → Inbox settings | 40–50/inbox/day for fully warmed; 20/inbox/day during soft launch |
| 3.4 Inbox rotation | Instantly → Campaign settings | Rotation enabled, correct inbox pool assigned |
| 4.1 Warmup enrollment | Instantly → Warmup settings | All inboxes enrolled, warmup showing Active |
| 4.2 Warmup timeline tracked | External spreadsheet or tracker | Warmup start date documented per inbox |
| 4.3 Warmup concurrent with campaigns | Instantly → Warmup settings | Warmup shows Active even with campaigns running |
| Item | Tool | Setting | Verification |
|---|---|---|---|
| 5.1 Verified contact list | Quarvio | Purchase pre-verified contacts | Bounce rate below 2% on first send |
| 5.2 ICP filter applied | Instantly → Leads | Upload filtered list only | Review list before import |
| 5.3 Correct campaign upload | Instantly → Leads import | Confirm campaign name before upload | List shows in correct campaign |
| 5.4 Suppression list | Instantly → Suppression | Import all prior opt-outs | Suppression list non-empty |
| 5.5 Unsubscribe line | Sequence email content | "To opt out, reply with 'unsubscribe'" | Present in every email in sequence |
| 6.1 Postmaster monitoring | Google Postmaster Tools | Weekly review of domain reputation | Calendar reminder set |
| 6.2 Blacklist monitoring | MXToolbox | Monthly review | Calendar reminder set |
Symptoms: MXToolbox SPF checker shows "SPF Record Failed" or "Multiple SPF Records Found" for the sending domain. Authentication check for the domain shows SPF as failing.
Root causes: Two SPF records exist for the domain (only one is allowed per domain). SPF record syntax is incorrect. DNS changes have not propagated yet (propagation takes up to 48 hours). The inbox provider's server is not included in the SPF record.
Fix: Log into the domain registrar's DNS management. Search for all TXT records containing "v=spf1." If more than one exists, delete the duplicates and consolidate all authorized senders into a single SPF record. Inframail configures SPF automatically, but if an existing SPF record was already present on the domain before provisioning, a merge conflict can occur. Verify the record syntax shows exactly one v=spf1 record. Re-check in MXToolbox after 24–48 hours for propagation.
Prevention: Before provisioning Inframail inboxes, verify no existing SPF record exists on the sending domain. Register fresh sending domains where possible to avoid pre-existing DNS conflicts.
Symptoms: MXToolbox DKIM checker shows "DKIM Record Not Found" or "DKIM Record Invalid" for the sending domain's selector. Emails are not being signed or signatures are not verifying.
Root causes: DKIM selector used in the check does not match the selector configured during Inframail provisioning. DNS propagation not yet complete. DKIM key was overwritten by a second provisioning step.
Fix: In Inframail, check the DKIM selector name configured during provisioning. In MXToolbox's DKIM checker, enter the correct selector name (e.g., "selector1" or the custom selector from Inframail). Re-check 24–48 hours after provisioning for propagation. If the DKIM record is truly missing after propagation, contact Inframail support to confirm the DKIM configuration was applied correctly.
Prevention: Inframail configures DKIM automatically. Verify the selector in Inframail's dashboard matches what you enter in MXToolbox. Using a default selector name (selector1) is the most common configuration for Microsoft 365 accounts via Inframail.
Symptoms: Transactional emails or marketing emails sent from the same domain are being rejected or quarantined after DMARC was configured with p=reject. Recipients report missing emails.
Root causes: Other email-sending services (marketing automation, support ticketing, transactional email) were not included in the SPF record or configured with DKIM signing before DMARC p=reject was implemented. DMARC p=reject will reject any email that fails both SPF and DKIM alignment for that domain — including legitimate sends from unconfigured services.
Fix: If using p=reject and legitimate email is being rejected, temporarily roll back to p=quarantine while auditing all services that send email from the domain. Add each service to the SPF record and configure DKIM signing for each. Return to p=reject after all legitimate senders are authenticated.
Prevention: For dedicated cold email sending domains (separate from the primary business domain), p=reject is safe because the only service sending from that domain is Inframail via Instantly. The problem occurs when p=reject is applied to the primary business domain without auditing all senders first.
Symptoms: Adding Inframail inboxes to Instantly fails with SMTP connection error. Inboxes show as "Connection failed" or "Authentication error" in Instantly.
Root causes: SMTP credentials entered incorrectly (wrong password, wrong server address). Microsoft 365 SMTP AUTH is not enabled for the mailbox. Two-factor authentication is interfering with SMTP authentication.
Fix: In Inframail, retrieve the exact SMTP credentials for the inbox (server, port, username, password). In Instantly, use the "Add Inbox" flow with SMTP/IMAP credentials and enter the exact Inframail credentials. Verify SMTP AUTH is enabled in the Microsoft 365 account settings for the inbox. Inframail should handle this during provisioning, but verify in the Microsoft 365 admin panel if connection issues persist.
Prevention: Use Inframail's provisioning workflow to add inboxes to Instantly where available — direct provisioning avoids manual SMTP credential entry errors.
Symptoms: Inboxes show as enrolled in Instantly's warmup network but warmup activity log shows zero sends after 48 hours. Warmup score is not initializing.
Root causes: Inboxes are enrolled but not connected (connection failure prevents warmup sends). Warmup is paused at the workspace level. Daily warmup send limit is set to 0.
Fix: In Instantly, check each enrolled inbox to confirm its connection status shows Connected. Check the warmup settings to verify the daily warmup email count is set above 0 (default is typically 10–20 per inbox per day). Check whether warmup is paused globally at the workspace settings level.
Prevention: After enrolling each inbox in warmup, verify the activity log shows the first warmup send within 24 hours. If no sends appear after 24 hours, investigate connection and settings immediately.
Symptoms: Domain is in warmup, sends are happening, but Postmaster Tools shows "Not enough data" or no reputation tier for the domain after 2 weeks.
Root causes: Domain verification incomplete (DNS TXT verification record added but not confirmed in Postmaster). Warmup sends not reaching Gmail addresses at sufficient volume. Postmaster data lags by 1–2 weeks from the actual send date.
Fix: In Postmaster Tools, verify the domain shows a green checkmark confirming verification is complete (not just "pending"). If verification is pending, recheck the DNS TXT record at the domain registrar. Per Woodpecker's cold email data, Postmaster data typically begins appearing at week 3–4 for a correctly verified domain. Treat "Not enough data" at week 2 as normal; investigate if it persists at week 5.
Prevention: Complete domain verification in Postmaster Tools on day one of domain setup. Verify the confirmation checkmark appears before beginning warmup. Data will start appearing automatically as warmup volume accumulates.
Symptoms: First cold campaign send generates bounce rate above 8%. Postmaster reputation drops immediately. Sending capacity is reduced by Instantly as a protective measure.
Root causes: Contact list not verified. List was sourced from an aggregator with outdated data. List contains a high proportion of role-based addresses. Contacts were enriched from social profiles rather than sourced from a verified B2B data provider.
Fix: Pause the campaign immediately. A bounce rate above 5% in a single campaign can cause domain reputation damage that takes 4–6 weeks to recover from. Replace the contact list with pre-verified contacts from Quarvio. Resume at low volume (5–10/inbox/day) with the verified list and monitor bounce rate on the first 50 sends before scaling.
Prevention: Checklist item 5.1 (contact list verification) is non-negotiable. Unverified contacts generate bounce rates that damage domain reputation faster than any other single failure mode.
Symptoms: Prospects who opted out of previous campaigns are receiving emails from new campaigns. Opt-out contacts are responding with frustration. Suppression list is in Instantly but new campaign sends are reaching opted-out contacts.
Root causes: Suppression list was configured as campaign-specific rather than global. New campaign was created without inheriting the global suppression list. Opted-out contacts replied to a different email thread whose reply detection was not mapped to the suppression list.
Fix: In Instantly, verify the suppression list is configured as a global suppression list that applies across all campaigns in the workspace, not as a per-campaign suppression list. Check new campaigns to confirm they show the global suppression list as active. Manually add any recently opted-out contacts who were not captured by the suppression list.
Prevention: Configure the suppression list as global at workspace setup, not campaign by campaign. Every new campaign should inherit the global suppression automatically without requiring manual steps per campaign.
Before launching any new campaign (even on an established domain), run a compressed version of the full 25-item checklist:
Authentication audit (5 minutes):
Inbox and warmup audit (5 minutes):
Contact and compliance audit (5 minutes):
A pre-campaign audit that takes 15 minutes catches the silent failures that would otherwise show up as poor performance after 2–3 weeks of sending.
BIMI (Brand Indicators for Message Identification) is an emerging email standard that displays a brand logo next to emails in supported clients (including Gmail for Google Workspace accounts). BIMI requires a DMARC policy of p=quarantine or p=reject, and a Verified Mark Certificate (VMC).
For cold email sending domains specifically, BIMI implementation is an optional but meaningful trust signal. Recipients who see a brand logo associated with an email are less likely to mark it as spam. Implementation requires DMARC at p=quarantine minimum and a VMC certificate from a qualified certification authority.
BIMI is not required for baseline cold email deliverability but represents the next level of authentication investment for operations at 50,000+ sends per month where marginal deliverability improvements have material revenue impact.
The 25-item pre-launch checklist is completed once per new domain/inbox setup. The following ongoing maintenance checklist applies monthly:
| Item | Frequency | Tool | Action if failing |
|---|---|---|---|
| Blacklist check | Monthly | MXToolbox | Submit delisting, pause sends |
| Postmaster reputation review | Weekly | Google Postmaster Tools | Reduce sends if below High |
| Warmup activity confirmation | Weekly | Instantly | Reconnect inbox if warmup stopped |
| Suppression list update | After each campaign | Instantly | Import new opt-outs |
| DMARC report review | Monthly | DMARC reporting tool | Investigate any unauthorized sends |
| Domain retirement review | Quarterly | Domain lifecycle tracker | Begin warming replacement domains at month 9 |
The pre-launch checklist and the monthly maintenance checklist together create a complete infrastructure governance process. Operations that run both consistently outperform those that set up correctly but skip ongoing maintenance.
| Need | Tool | Notes |
|---|---|---|
| Verified B2B contacts | Quarvio | One-time purchase, no subscription |
| Email inboxes | Inframail | Microsoft 365 inboxes, auto DNS |
| Cold email sending | Instantly | Sequences, warm-up, reply tracking |
| LinkedIn outreach | Aimfox | Connection campaigns, Unibox |
Which checklist item is most commonly missed by new cold email senders?
DMARC configuration is the most commonly missed authentication item — SPF and DKIM are widely understood, but DMARC is less familiar and skipped on a significant proportion of new setups. Warmup timeline adherence is the most commonly skipped operational item: new senders start cold campaigns before completing the 4–6 week minimum warmup. Both failures are silent — they don't generate error messages, they just reduce inbox placement.
How long does it take to complete the full pre-launch checklist?
The one-time setup tasks (domain registration, authentication configuration, Instantly connection, Postmaster Tools enrollment) take 1–2 hours with Inframail's automatic DNS configuration. The warmup period (items 4.1–4.3) takes 4–6 weeks. The contact preparation tasks (5.1–5.3) depend on list size and source. Plan for 4–6 weeks from checklist start to first cold send.
Do I need to redo this checklist for every new domain I add?
Yes, for sections 1 and 2 (domain and authentication items). Section 1 items 1.1–1.5 apply to every new sending domain. Section 2 items 2.1–2.6 must be verified for every new domain. Sections 3–7 apply to every new inbox and campaign. The checklist is a per-domain-and-inbox setup verification, not a one-time-ever process.
What is the minimum viable setup for a brand-new cold email operation?
The minimum viable setup: 1 sending domain, 3 inboxes, SPF/DKIM/DMARC configured (automatic via Inframail), all inboxes connected to Instantly with warmup enabled, Postmaster Tools enrollment. This supports approximately 2,500–3,000 contacts per month after the 4–6 week warmup period. The 25-item checklist still applies in full — a "minimum viable" setup does not mean skipping any items.
Can I skip any of the 25 checklist items for a test campaign to just see if the channel works?
No. The checklist items that are most commonly skipped are the ones that cause silent failures: DMARC configuration (missing on 30–40% of new setups), warmup completion, and suppression list setup. A test campaign launched without these items will achieve poor inbox placement, generating false-negative results that suggest the channel doesn't work when the actual problem is infrastructure. The 25 items are the conditions required to get valid test results, not optional additions for when the channel is "proven." Set up correctly once, then test.
What is the correct order to complete the 25 checklist items?
Complete the items in the order they appear in the checklist: domain setup first (items 1.1–1.5), then authentication (2.1–2.6), then inbox setup (3.1–3.4), then warmup (4.1–4.3), then contact preparation (5.1–5.3), then compliance (5.4–5.5), then monitoring setup (6.1–6.2). This order reflects technical dependencies: authentication requires domains to exist, warmup requires authenticated inboxes to be connected, and campaigns require warmup to be in progress. Attempting items out of order (e.g., connecting inboxes before authentication is verified) creates configuration states that need to be corrected.
How do I verify that each authentication record is correctly configured after Inframail provisioning?
For each authentication record, use the corresponding MXToolbox checker: SPF at mxtoolbox.com/spf.aspx, DKIM at mxtoolbox.com/dkim.aspx, DMARC at mxtoolbox.com/dmarc.aspx. Enter the sending domain name in each checker. The expected result for each: SPF shows "SPF Record Found" and "Passed." DKIM shows a valid signature with the selector matching the one configured in Inframail. DMARC shows a record found with a policy (p=none, p=quarantine, or p=reject). If any record fails immediately after provisioning, wait 24–48 hours for DNS propagation before concluding there is a configuration problem — DNS records take time to propagate globally.
What should I do if my domain registrar doesn't support DMARC configuration?
All major domain registrars support adding DNS TXT records, which is how DMARC is configured. DMARC is not a registrar-specific feature — it is a DNS TXT record that can be added through any registrar's DNS management interface. If your registrar's DNS management interface is limited, consider using Cloudflare's free DNS management service as an alternative DNS provider for the sending domain — Cloudflare allows full DNS record management including all DMARC configurations. Inframail configures DMARC automatically during provisioning; the record appears in the domain's DNS once Inframail's setup is complete.
How do I know if warmup is actually working after I enroll inboxes?
Three indicators that warmup is working correctly: (1) The warmup activity log in Instantly shows sends and engagement (opens, replies) occurring for each enrolled inbox within 24–48 hours of enrollment. (2) The warmup score in Instantly is initializing and beginning to increase after the first week. (3) Google Postmaster Tools begins showing data for the domain by week 3–4. If any of these indicators are absent after 48 hours of warmup enrollment, check inbox connection status in Instantly and verify authentication records are passing in MXToolbox — both are common root causes of warmup stalling.
What should I do if Google Postmaster Tools never shows data for my sending domain?
Verify domain verification is complete: the DNS TXT verification record must be added to the domain's DNS settings and confirmed with a green checkmark in Postmaster Tools. Without this, no data will appear regardless of send volume. If verification is confirmed complete and data still has not appeared after week 5, confirm that Instantly's warmup network is sending to Gmail addresses at sufficient volume — Postmaster only shows data when the domain has sent enough email to Gmail accounts to generate statistical data. Postmaster typically begins showing data at week 3–4 for a correctly set-up domain with active warmup.
What is the difference between a hard bounce and a soft bounce in the context of this checklist?
A hard bounce is a permanent delivery failure: the email address does not exist, the domain is invalid, or the recipient server has permanently rejected the address. Hard bounces damage domain reputation because they indicate poor list quality. The bounce rate threshold in this checklist refers to hard bounces. A soft bounce is a temporary delivery failure: the recipient's mailbox is full, the server was temporarily unavailable, or the message was too large. Soft bounces typically resolve on retry and do not damage reputation. Quarvio verified contacts eliminate hard bounces by verifying each address is reachable before delivery. The 2% bounce rate limit in checklist item 5.1 refers specifically to hard bounce rate.
Do I need separate monitoring setup for Outlook/Microsoft 365 domains specifically?
Yes. Google Postmaster Tools monitors Gmail deliverability specifically. Microsoft has an equivalent tool called Smart Network Data Services (SNDS) for monitoring deliverability to Outlook and Microsoft 365 accounts. In SaaS and enterprise sales, a significant proportion of prospects use Microsoft 365. Adding the sending domain to both Google Postmaster Tools (item 1.5 in the checklist) and Microsoft SNDS provides complete visibility into deliverability for both major mailbox provider ecosystems. Microsoft SNDS monitoring is not included in the standard 25-item checklist but should be considered mandatory for operations where the target audience uses Microsoft 365 at significant rates.
Every checklist item protects domain reputation. Contact verification is the most correctable one.
Missing authentication or warmup takes weeks to fix. Sending to an unverified contact list that generates 5% bounces can damage domain reputation in a single campaign. Quarvio delivers pre-verified B2B contacts that check item 5.1 from the list before the first send.
