on this page
Mail¶
- Email Architecture: MUA/MSA/MTA/MDA roles, store-and-forward, envelope vs headers, ports
- The SMTP Protocol: the raw conversation, reply and enhanced status codes, STARTTLS vs implicit TLS, AUTH, bounces
- DNS and Mail Routing: MX, PTR and FCrDNS, relaying vs final delivery, smart hosts, split-horizon DNS
- Email Authentication and Anti-Spam: SPF, DKIM, DMARC, sender requirements, MTA-STS/DANE, DNSBLs, greylisting
- Mailbox Formats and Delivery: mbox vs Maildir, local vs virtual mailboxes, aliases, Dovecot LMTP
- Overview and Architecture: the daemon pipeline, queues,
postconf, lookup tables and the Berkeley DB migration, core identity settings
- Installation and Basic Configuration: install, a minimal
main.cf, firewall, testing with mail/telnet/swaks
- Relaying Outbound Mail: null client,
msmtp (e.g. feeding an existing containerized relay), Gmail/Mailgun/Proton/port 465 smart hosts, address rewriting, per-sender relays
- Virtual Domains, Mailing Lists and Virtual Mailboxes: forwarding domains,
/etc/aliases lists, SQL + Dovecot LMTP, submission service, PostfixAdmin, auto-reply
- TLS Encryption: security levels, modern parameters, certificates, per-domain policy, DANE/MTA-STS, troubleshooting
- Security and Hardening: open relay testing, restrictions, postscreen, postgrey, header checks, rspamd, AUTH brute-force protection, checklist
- Administration and Queue Management:
postqueue, postsuper, postcat, bulk operations, aliases, logs with and without syslog
- Troubleshooting: log severities, a catalogue of errors and fixes, debugging workflow
- Legacy Reference: Two-Host Local Network Setup: historical home-network relay setup, kept for reference
clients/: terminal and command-line mail clients¶
- The
mail Command: mailx vs s-nail vs GNU Mailutils (and their conflicting -a flags), attachments, HTML, sendmail -t, cron, swaks
- Mutt: IMAP/SMTP, Gmail with app passwords or OAuth2, multiple accounts, passwords via
pass, address books, offline Maildir, debugging
- Mutt and GPG: GPGME vs classic
gpg.rc, gpg-agent/pinentry, autocrypt, troubleshooting
- NeoMutt: what the fork adds, migrating, sidebar, notmuch, header-cache backends
- Proton Mail Bridge: desktop and headless Bridge, Mutt/NeoMutt config, certificates, mbsync backups
- SquirrelMail: project status, install,
conf.pl, hardening, migrating to Roundcube
- Zimbra: Architecture and Administration: components, licensing, install prerequisites,
zmcontrol/zmprov/zmmailbox, the bundled Postfix, backups
- Zimbra: TLS Certificates and SNI:
zmcertmgr, Let's Encrypt renewal, per-domain certificates with SNI, troubleshooting