How do I force TLS authentication by SMTP - Plesk with submission

[adrik]

Hello,

I am using PLESK 8.3 with "Enable message submission" ON and Set "Relaying" to CLOSED. Everything works just fine, but I want to force my SMTP users to use TLS encryption only and block them using just simple PLAIN authentification. I read about setting FORCE_TLS=1 on some QMAIL sites (http://qmail.jms1.net/), but I am not sure where to set it, not to conflict with PLESK.

Thank you.

Adrik

 

[DaDomainMasta]

hi Adrik,
i have checked the site, it looks like like the author is running smtp in deamon mode, not through x/inetd as it is in Plesk, so recommendations applied directly less likely will work. also i have checked xinetd config for smtp_psa and qmail init script and saw no placeholders for the variables mentioned. i would avoid playing with these actually.

 

[adrik]

Thank you very much,

till now I did not find the solution.

My goal is to allow only encrypted authorization methods for SMTP. No encrypted authorization should be blocked. (LOGIN, PLAIN). Doesnt matter if the solution is SSL or TLS.

I have already tried it with SSL, but I did not find the solution as well. I can allow SMTP authorisation in Plesk by setting Relay options to : "authorization is required - SMTP". SSL ist working fine, but the PLAIN authorisation is working also. I dont like it, if anybody can see the password with nmap. Anyway, most of my clients are using the same password form mail/ftp/ssh.

Adrik