SOLVED CPANEL-40103 - About the Protocols Enabled in WHM's Mailserver Configuration screen

Kent Brockman

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Hello guys, just wondering about these Mailserver settings: why some servers show IMAP, IMAPS, LMTP, POP3, POP3S and others show just IMAP, LMTP, POP3?

What's the purpose of IMAPS and POP3S and why there is nearly no documentation about those two protocols?

Thanks!
 

cPRex

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Hey there! We were actually talking about this internally the other day, and you're right, there isn't much out there on that.

From what I can see, the "s" is when you specifically want to enforce a secure connection. IMAP itself needs to be passed starttls in order to get a secure connection, where IMAPS doesn't. We found some good details here, although I'm guessing your search found this as well:


Basically, it's the same security with fewer steps on the server side, but not a whole lot is using it yet.
 

Kent Brockman

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Hi, yes, thanks for the info, and in fact it's similar to what I found.

What I couldn't find and would love to read some words from cPanel staff is why some servers show the IMAPS and POPS options and other doesn't. What settings allow/disallow these protocols?
 

quietFinn

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We have one server with CloudLinux 6, in that there is no IMAPS or POP3S, newer servers have those.
 
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Kent Brockman

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I'm not aware of any settings that should keep those from showing up. Are the ones where it is not showing up using older cPanel versions or older operating systems?
All the servers has same cPanel version and same OS version, CentOS 7.9. Mailserver and Exim are configured equally on all servers. Cannot understand WHY some will offer the POP3S and IMAPS options and others don't...... It must exist one explanation. Can you escalate this or should I open a ticket for further investigation?
 

cPRex

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Kent Brockman

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Thanks for the feedback.
What I wanted to confirm is: although the IMAPS and POP3S options are hidden, this doesn't make it unusable, right?
 
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Kent Brockman

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Jan 20, 2008
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Well, based in the ticket reply, I was able to write this to solve the issue:

Execute: nano /var/cpanel/conf/dovecot/main

Delete the line containing this:
_use_target_version: '2.2'

Save. Exit editor. Then execute this:

mv -v /var/cpanel/conf/dovecot/main.cache{,-backup} && /scripts/builddovecotconf && /scripts/restartsrv_cpsrvd --hard

And voila! This solved the issue in all the affected servers.
 
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