I hope I’m asking in the right place. Could be re-titled Email client/ IMAP / VPN weird issues.
Recently, my Thunderbird stopped connecting and returns a server timeout message. I noticed this is for every email account and they are on 2 different servers so I believe this is a local issue instead of server problems.
I then re-installed Evolution and it also returns a timeout, this one showing Socket I/O timed out.
Perhaps unrelated (or not), my OVPN client began killing my wifi connection every time OVPN starts. I have to close the OVPN client and toggle wifi off and on to connect once again.
All of this is to say, I have no idea where to look from here. All I can find in search relating to these errors is very old and most are dealing with windows and IMAP. Can anyone point me in the direction to try and find what’s going on?
Strangest thing…I switched my VPN on (not using the OVPN client) and all of a sudden email poured in. Turned VPN off, email stopped flowing. ISP port block maybe?
consumer ISP often block outgoing mail on port 25 to avoid malware on customer system which sends spam directly to mailserver port 25 - but IMAP is not blocked as it is the defacto client access unencrypted on port 143 and TLS on port 993.
This is making a lot of sense. It appears that the VPN client is hijacking (in a good way) dns because I’ve told it which dns to use, but as the client is having an error communicating with it’s servers, it’s killing the connection.
I’m going to follow your testing instructions. Thank you!
The first part - hijacking - technically it is done to prevent dns leaks.
VPN is used for privacy issues and DNS leaking is desribing the situation where the addresses for hosts you visit while using VPN is in fact provided by your ISP/router and not by the VPN provider.
Your second part - did you manually edit your DNS settings to set a different nameserver than the one provided by your VPN? You should take great care when modifying nameservers - it is easily misconfigured thus creating issues precisely like your current.
OpenVPN is known to cause DNS leaking especially with NetworkManager.
The arch wiki contains extensive information on using OpenVPN and advise on how to prevent leaking.