Blog
Cold email infrastructure, explained
Practical, no-fluff guides on the records and checks that decide whether an outbound launch is ready or risky.
Latest
August 28, 2026
Troubleshooting · 12 min read
Microsoft 365 cold email deliverability troubleshooting
Troubleshoot Microsoft 365 cold email by separating blocked senders, Exchange Online limits, authentication failures, remote rejections, junk placement, and low replies.
By OutboundQA · Reviewed by OutboundQA product review
Troubleshooting
How to diagnose a sudden drop in cold email replies
Diagnose a sudden cold email reply drop by separating tracking errors, reply routing, delivery failures, audience changes, and message problems in a fixed order.
August 27, 2026 · 10 min read
By OutboundQA · Reviewed by OutboundQA product review
Agency
Cold email infrastructure audit template for agencies
Download a cold email infrastructure audit template for agencies. Track assets, owners, evidence, blockers, fixes, reruns, and client signoff in CSV or Markdown.
August 26, 2026 · 7 min read
By OutboundQA · Reviewed by OutboundQA product review
Monitoring
Domain reputation monitoring for cold email agencies
How agencies monitor domain reputation risk across a client portfolio: early-warning signals, an approved baseline, incident history, and client-ready proof.
August 26, 2026 · 7 min read
By OutboundQA · Reviewed by OutboundQA product review
Troubleshooting
Instantly deliverability troubleshooting checklist
Troubleshoot Instantly deliverability by separating paused campaigns, auto-paused high-bounce sends, hard and soft bounces, spam placement, and infrastructure faults before you touch DNS.
August 26, 2026 · 10 min read
By OutboundQA · Reviewed by OutboundQA product review
Monitoring
How to monitor multiple cold email sending domains
A centralized way to monitor a fleet of cold email sending domains: track drift across domains, set alert severity, assign ownership, and report to clients.
August 26, 2026 · 9 min read
By OutboundQA · Reviewed by OutboundQA product review
Troubleshooting
Smartlead deliverability troubleshooting checklist
Troubleshoot Smartlead deliverability by separating stopped sends, sender bounces, lead bounces, missing seed messages, spam placement, and infrastructure faults.
August 26, 2026 · 9 min read
By OutboundQA · Reviewed by OutboundQA product review
Troubleshooting
Cold email bounce rate troubleshooting checklist
Diagnose a high cold email bounce rate in a safe order: list quality, recipient domain readiness, sending DNS and authentication, provider blocks, and reputation.
August 25, 2026 · 9 min read
By OutboundQA · Reviewed by OutboundQA product review
Troubleshooting
Why are my emails going to spam when SPF, DKIM, and DMARC pass?
SPF, DKIM, and DMARC can pass while emails still go to spam. Check reputation, tracking hosts, message evidence, SMTP identity, and recipient filtering.
August 25, 2026 · 8 min read
By OutboundQA · Reviewed by OutboundQA product review
Blacklists
Blacklist preflight before a cold email launch
How to run a blacklist preflight across domains, tracking domains, and sending IPs before a cold email campaign goes live.
July 23, 2026 · 2 min read
By OutboundQA · Reviewed by OutboundQA product review
Domain Age
Cold-domain alerting before outbound campaigns
How to alert on new or risky cold email domains before a campaign starts, including age, expiry, authentication, blacklist, and DNS drift signals.
July 23, 2026 · 2 min read
By OutboundQA · Reviewed by OutboundQA product review
Launch QA
Cold email launch verdicts: Ready, Needs Fix, and Do Not Launch
How to turn SPF, DKIM, DMARC, DNS, tracking, blacklist, and SMTP evidence into a clear cold email launch decision.
July 23, 2026 · 2 min read
By OutboundQA · Reviewed by OutboundQA product review
DKIM
DKIM selector mismatch in cold email
How DKIM selector mismatch happens, why it breaks authentication, and how to verify the selector before a cold email launch.
July 23, 2026 · 2 min read
By OutboundQA · Reviewed by OutboundQA product review
Agency
Multi-client cold email QA for agencies
A repeatable QA workflow for agencies launching outbound campaigns across many clients, domains, inboxes, tracking domains, and sending tools.
July 23, 2026 · 2 min read
By OutboundQA · Reviewed by OutboundQA product review
Deliverability
Seed-list testing vs infrastructure QA
The difference between seed-list inbox placement tests and infrastructure QA for cold email launches, and when to use each.
July 23, 2026 · 2 min read
By OutboundQA · Reviewed by OutboundQA product review
SMTP
PTR drift monitoring for custom SMTP egress
Why PTR and forward-confirmed rDNS drift can break custom SMTP sending, and what to check before and after a cold email launch.
July 23, 2026 · 2 min read
By OutboundQA · Reviewed by OutboundQA product review
SMTP
SMTP egress checks for cold email
The SMTP egress identity checks cold email teams need when they send through direct IPs: PTR, forward-confirmed rDNS, HELO, banner, and IP reputation.
July 23, 2026 · 2 min read
By OutboundQA · Reviewed by OutboundQA product review
Sending Tools
Sending-platform checks vs launch QA
Why Smartlead, Instantly, and other sender dashboards are not enough for full cold email launch QA across domains, inboxes, tracking, blacklist, and SMTP egress.
July 23, 2026 · 2 min read
By OutboundQA · Reviewed by OutboundQA product review
Tracking Domains
Tracking SSL expiry in cold email
Why tracking-domain certificate expiry breaks cold email links, how to monitor it, and when to alert before a campaign is affected.
July 23, 2026 · 2 min read
By OutboundQA · Reviewed by OutboundQA product review
Receiver requirements
Gmail, Yahoo, and Microsoft receiver requirements for cold email
A practical receiver requirements checklist for cold email agencies covering SPF, DKIM, DMARC, alignment, one-click unsubscribe, PTR, TLS, and the evidence a browser check cannot prove.
July 20, 2026 · 6 min read
By OutboundQA · Reviewed by OutboundQA product review
Sender Rules
Google and Yahoo sender requirements for cold email
Google and Yahoo sender requirements for cold email agencies: SPF, DKIM, DMARC, alignment, one-click unsubscribe, spam complaints, DNS, TLS, and launch signoff.
July 16, 2026 · 9 min read
By OutboundQA · Reviewed by OutboundQA product review
Tracking
Cold email tracking domain setup checklist
A cold email tracking domain setup checklist for agencies: choose the host, publish the CNAME, verify SSL, test redirects, check blacklist risk, and document launch signoff.
July 15, 2026 · 8 min read
By OutboundQA · Reviewed by OutboundQA product review
Launch Audit
How to audit a cold email setup before launch
Audit a cold email setup across sending domains, inboxes, tracking domains, and SMTP egress. Turn current evidence into one Ready, Needs Fix, or Do Not Launch decision.
July 11, 2026 · 11 min read
By OutboundQA · Reviewed by OutboundQA product review
Reports
Client-ready email deliverability report template for cold email agencies
A client-ready email deliverability report template for cold email agencies: executive summary, launch verdicts, DNS checks, tracking, blacklists, fixes, and signoff.
July 7, 2026 · 9 min read
By OutboundQA · Reviewed by OutboundQA product review
Cold Email Tools
Best cold email tools for agencies in 2026: a practical launch stack
A practical cold email tools stack for agencies: sending, verification, DNS checks, warmup, DMARC, enrichment, and pre-launch QA before a client campaign goes live.
July 6, 2026 · 12 min read
By OutboundQA · Reviewed by OutboundQA product review
Blacklists
Why your cold email domain landed on a blacklist, and how to check
How sending domains end up on blacklists, the lists that actually matter for cold email, how to check before launch, and what to do if you are listed.
June 16, 2026 · 3 min read
By OutboundQA · Reviewed by OutboundQA product review
DMARC
Do I need DMARC for cold email? Setup and launch checklist
Yes. If you send cold email, publish DMARC alongside SPF and DKIM. Learn what it proves, how to start safely, and how to check the live record.
June 10, 2026 · 3 min read
By OutboundQA · Reviewed by OutboundQA product review