Email Infrastructure guides and tutorials
8 practical MailSlurp resources
Articles and guides
MTA and SMTP: How Mail Transfer Agents Use SMTP To Move Email
Learn how MTA and SMTP fit together, where mail submission ends and relay begins, and how to test routing, queues, retries, and delivery behavior safely.
Read moretechnicalSMTP Relay Services: How To Compare Providers for Application Send, Relay Control, and Release Safety
Compare SMTP relay services by workflow fit, sender controls, authentication, diagnostics, and testing needs so you choose the right provider for application email and relay operations.
Read moretechnicalEmail Protocols Explained: SMTP, IMAP, POP3, and Where APIs Fit
Learn the main email protocols, what SMTP, IMAP, and POP3 each do, and how to choose the right send, receive, and sync model for apps, support, QA, and product email.
Read moretechnicalSMTP Server Configuration Checklist: Host, Port, TLS, Auth, and DNS
Configure SMTP correctly with a practical checklist for host, port, TLS, authentication, sender identity, and testing from staging to production.
Read moretechnicalSMTP 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 moretechnicalPort 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 moretechnicalSMTP Service Guide: Run Your Own vs Managed Platform
Compare self-hosted SMTP and managed SMTP services with a practical decision matrix, operational checklist, and rollout plan for product teams.
Read moretechnicalHow to Set Up a Fake SMTP Server for Local and CI Tests
Run smtp4dev locally, send a sample email, and assert its recipient, subject and body with a downloadable Python example for local and CI tests.
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