SMTP
- How to Choose the Right SMTP Port (Port 25, 587, 465, or 2525)
- Still Confused With SMTP Ports? Read This
Mail server (postfix)
Postfix
- https://willem.com/blog/2019-09-10_fighting-backscatter-spam-at-server-level/
- prevent open relay
- postfix - users are geting mail from them self that they did not send
- enable SASL postfix
- Postfix SASL howto
- Debian postfix anti Span
- Postfix reject RBL
- Running a mail server (linode)
- Postfix and SASL
- Hardening Postfix
- Postfix-Cyrus-Web
- Test SASL
- How To Install and Configure Postfix as a Send-Only SMTP Server on Ubuntu 20.04
- DMARC Postfix Setup
- Set Up OpenDMARC with Postfix on Ubuntu to Block Email Spoofing/Spam