Using POP3 Protocol with Outlook Issue: Cannot Synchronize Subscribed Folders

OS type and version Rocky Linux 9.3
Webmin version 7.8.2
Virtualmin version 2.105
Related packages Dovecot

Hey Guys!

I have a very odd issue with POP3 protocol, I had to move my old Outlook messages from old server to the new one, I have exported all messages as Outlook’s PST file and imported it with the following settings:

Incoming Server
Server Type: POP3
Server Name:
Port: 995
Encryption: SSL/TLS

Outgoing Server
Encryption: SSL/TLS
Port: 465
And Other Credentials

Outlook successfully imported folders but suddenly stopped synchronizing and generated the following error for all emails using the POP3 protocol.

NOTE: Sync issue is not persistent, it works for a while and stops syncing for 4-5 hours and is back to work, Dovecot service is working and RoundCube can log in/Send and Receive

Task ''Synchronizing subscribed folders for EMAIL.' reported error (0x800CCC0E) : 'Outlook cannot synchronize subscribed folders for [EMAIL]. Error: Cannot connect to the server.

– Mailbird App –
I tried Mailbird and it completely imported all PST file and worked great for a couple of days but suddenly stopped and generated the following message:

[EMAIL] Error getting messages

This is typically caused by another email client checking for messages at the same time, or checking for messages too often.

I believe that the Mailbird message because I tried to use Outlook simultaneously.

The Dovecot service is working, and Rouncube can Login, Send and Receive messages.

Could it be related to the Dovecot?, Any Thoughts?


in general POP3 is a one-way protocol – your server receives a message, later your PC connects and DOWNLOADS the msg to your PC’s hard drive, then immediately (or days later depending on your settings), DELETES the message from the server :smile:

often with having the server under your control, many will use the IMAP protocol — have you explored that as an alternative to POP3?

And I am guessing here – does RoundCube use IMAP?

Just some general random thoughts here !!

IMAP working properly my friend.

POP3 working but sometimes during the syncing process, it generates the issue I mentioned above.

I need to keep some emails using POP3 locally.

Thank You

POP3 protocol specifies that only one device can access at a time, so yes two email clients can clash.

Just curious, why use Roundcube?

RoundCube for testing send/receive when Outlook stops Syncing, but I’m asking about the error msg appears randomly, Outloook works perfectly for 5/6 hours and stops for a while and back to work.

Thank You

Something in the Router :grinning: Fixed after resetting the router settings. I won’t delete this post because it could be useful for others with the same case.

Thank You

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