MailSlurp resources
Guides - Page 5
Practical guides for MailSlurp messaging, testing, reliability, extract, account setup, and procurement workflows.
Posts
DNS PTR Record: Setup, Validation, and Troubleshooting for Email Sender Identity
Learn what a DNS PTR record does, who controls it, how to validate reverse DNS correctly, and how to troubleshoot PTR issues that affect sender trust and email delivery.
Read more technicalDMARC Reject: What Happens, Why Legitimate Mail Gets Blocked, and How To Roll It Out Safely
Learn what DMARC reject means, how receivers handle failing mail under reject policy, and how to avoid blocking legitimate messages during enforcement.
Read more technicalDMARC Fail: What It Means, Common Causes, and How To Fix It
Understand what a DMARC fail result actually means, why SPF or DKIM can pass while DMARC still fails, and how to troubleshoot alignment without guessing.
Read more technicalDMARC Digests: How To Summarize Reports Into Action
Learn what a DMARC digest should include, how to read daily and weekly summaries, and how to turn aggregate report data into sender-health action.
Read more technicalSMTP Mail Protocol Guide: How Simple Mail Transfer Protocol Works
Learn how SMTP works as the mail transport protocol for submission and relay, how it differs from IMAP and POP3, and how to test SMTP workflows safely.
Read more technicalPort 25: What It Is, Why It Gets Blocked, and What To Use Instead
Learn what port 25 is for, why cloud providers often restrict it, how it differs from ports 587 and 465, and when SMTP relay on port 25 is still appropriate.
Read more technicalGoogle Workspace MX Records: Setup, Verification, and Common Mistakes
Learn which Google Workspace MX records to publish, how to verify Gmail routing after DNS changes, and which migration mistakes break inbound mail.
Read more technicalSPF Verification Guide: How to Check and Validate SPF Records
Learn how SPF verification works, how to check an SPF record correctly, and how to interpret pass, fail, softfail, and neutral results.
Read more technicalSpam Filter Guide: How Email Spam Filters Work and What They Flag
Learn how spam filters evaluate email, which signals trigger filtering, and how teams can test auth, content, and sender reputation before they send.
Read more technicalOutlook SMTP Settings Guide: Server, Port, TLS, and Common Errors
Learn the typical Outlook SMTP settings, how Outlook.com differs from Microsoft 365, and how to troubleshoot auth and relay failures safely.
Read more technicalMX Records Guide: What Mail Exchanger Records Do and How to Check Them
Learn what MX records are, how mail exchanger priority works, and how to check MX setup when domains are not receiving mail as expected.
Read more technicalIMAP vs POP3: Differences, Sync Behavior, and Which Protocol to Use
Compare IMAP vs POP3, understand where SMTP fits, and choose the right protocol for synced inboxes, offline access, and test environments.
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