akust0m

Well-Known Member
Feb 19, 2016
70
4
8
Melbourne
cPanel Access Level
Root Administrator
Hey :)

I understand about SSL/TLS connections between client and server, but what about between MTA's?

Will cPanel attempt to send via TLS by default to other MTA's? Will Exim in cPanel accept mail and send mail in plain text if the remote MTA doesn't support TLS for some reason?

Is non-encrypted delivery common between MTA'S?

Are there settings in cPanel to configure this behavior for Exim?

Thanks in advance :)
 

cPanelLauren

Product Owner
Staff member
Nov 14, 2017
13,296
1,268
313
Houston
Will Exim in cPanel accept mail and send mail in plain text if the remote MTA doesn't support TLS for some reason?
The sending MTA will connect over whichever protocol is specified by the sender's client and the receiving MTA must accept that protocol. If the sending server requests a connection over TLSv1.2 the receiving server must accept that protocol otherwise the connection is refused.

Will Exim in cPanel accept mail and send mail in plain text if the remote MTA doesn't support TLS for some reason?
The protocol is deemed by the client not the server, the client requests a connection over x protocol/s and the MTA facilitates that connection with the remote server.

Is non-encrypted delivery common between MTA'S?
The only reason a non-encrypted connection would be made would be if it was requested by the client.

You can modify the ciphers and protocols exim is able to use at WHM>>Service Configuration>>Exim Configuration Manager.

Thanks!