Email configuration best practices overview

Draft to brainstorm about the possibility of a new best practices configuration page. IF we want to continue with this and finish it, we will add it to the documentation and remove this wiki page.

Goal:

The Mailu solution is very complex. Most people don't know how to correctly configure Mailu. This page should inform you:

• What are the relevant settings?
• How-To change these settings. Per relevant subject describe how to configure it.
• best practices? This is what we advise!
• MAIN GOAL. Everything should be as easy to understand as possible. if it is too difficult, do not include it.

Structure of page itself. How we want it to be.

• General overview (or short list) of all features.
• How-To tweak/configure each security related setting/topic.
• Maybe best practices? What do we advise?

How to

• postfix
  • /etc/postfix/tls_policy.map > overrides/postfix/tls_policy
  • maybe fingerprinting could be added as well (need nextgens help for this)
• fail2ban (move this from the FAQ to this page)
• set mta-sts (domain must be configured as well with domain entry)
• ability spoof emails. Set wildcards/aliases (in gui).

#1902 docker-compose exec smtp cat /etc/postfix/tls_policy.map > overrides/postfix/tls_policy edit overrides/postfix/tls_policy as required then recreate the smtp container

Random related things: something you may want to document on the security page: One can use the following command from the admin container to benchmark how many rounds to configure in CREDENTIAL_ROUNDS : python3 -m timeit -n 1 -s "from passlib.hash import bcrypt_sha256" "bcrypt_sha256.using(rounds=12).hash('password')" ... tweaking rounds and the number of iterations as required

https://www.digitalocean.com/community/tutorials/how-to-configure-mta-sts-and-tls-reporting-for-your-domain-using-apache-on-ubuntu-18-04 https://aykevl.nl/apps/mta-sts/ Here's my overrides/nginx/mta-sts.conf; You also need to add mta-sts.example.com to HOSTNAMES to ensure that you get a valid certificate for it

  location @mta-sts {

return 200 "version: STSv1 mode: testing max_age: 86400 mx: mx.example.com\r\n"; }

  location ^~ /.well-known/mta-sts.txt {
    try_files $uri @mta-sts;
  }

Move this part to the general features page (https://mailu.io/master/)

• dkim
• dmarc
• arc
• spf
• antivirus
• antispam
  • realtime black listing
  • bayes learning
  • See https://rspamd.com/features.html
• Possibility to configure with fail2ban
• All postfix related stuff?
  • ?
  • ?
• all communication go through one secure front service
  • rate limiting on failed logon
    • per ip
    • per user
  • server side session management
  • session forgery protection