I'm having trouble setting up my Zimbra installation MTA. I am able to send and receive mail internally, and I'm able to receive mail externally as well. I'm fairly new to email/network administration, so beginner steps are appreciated.
Zimbra currently uses fetchmail to retrieve mail and deliver it. That aspect I was able to figure out and it is working correctly.
According to my ISP (hostpapa) in order to send mail using SSL/TLS encryption, the mail should be delivered to hp117.hostpapa.com:465.
When I send email to this port, all emails get redirected to the deferred queue and just sit there. The emails sit in the queue with the message:
"lost connection with hp117.hostpapa.com [18.104.22.168] while receiving the initial server greeting"
In my administration tab I've set up my MTA server, enabled authentication, and tried all settings both with TLS required and not required.
I have done some research on the initial server greeting error, and followed the instructions found here: Outgoing SMTP Authentication - Zimbra :: Wiki
This has enabled me to send emails externally, however, they do not appear to use any form of encryption (opening the "original message" does not reveal any use of SSL or TLS encryption).
This has been my journey thus far, any assistance in getting my SSL/TLS encryption up would be appreciated. Since I'm new to this whole shebang its entirely possible the encryption is working and I just don't know what to look for.
Thanks in advance.