GL-AXT1800 Firewall & Outlook

Hi, Just switching over to the GL-AXT1800 from a AC3100 router that I am using openWRT on, for the life of me I cannot find an article on how to let Outlook through the firewall using IMAP. No VPN set up on the GL-AXT1800 so it must be the Firewall blocking Outlook right? Switching back to my AC3100 everything works fine. I have read the firewall section of the manual but it’s gibberish to me, I’m not married to ‘Office365’ so if I have to ditch it in favour of a web based email that’s fine - unless it’s straightforward on the GL-AXT1800!? Cheers

Is ‘Outlook’ in this context an application on your PC? System Explorer (v7) → Connections can show what ports your PC applications are trying to use.

The default GL device firewall rules for outgoing traffic are permissive; there shouldn’t be anything blocking any LAN → WAN originating ports.

An IMAP server typically listens on port number 143. IMAP over SSL/TLS (IMAPS ) is assigned the port number 993.[2][3] (Internet Message Access Protocol, Wikipedia)

Office365 (now Microsoft 365) uses TCP 993 for IMAP.

The GL-AXT1800 router should not be blocking TCP 993 or outbound traffic by default, so it may be due to some other problem. Check your Outlook account setting to make sure it is using Port 993 and SSL/TLS and the authentication is correct.

I do not work for and I am not directly associated with GL.iNet

Interesting. This might be related. I just added a wifi-6 device to what was previously a flawless network using an axt1800, and now it appears as though TCP 993 is blocked.

The firewall should not be the problem here since it usually does not block outgoing connections.

So the issue will have a different reason.

The firewall is blank. I’ve tried to eliminate the axt1800 as the culprit, but in its absence, everything works.

Do you use Adguard for example?

Resetting the firmware solved the problem, whatever it was.