I have set up email notification for backup and it works on other computers that I have set up before OK. This computer I cant switch off firewall and think its blocking the email. I did add exception for port 25 and 587 but the email doesn’t come through. The duplicati log says 1 error which I presume is the sending of the email as the actual backup process completes successfully. What ports and programs should I be adding to the firewwall exception list to get this working. The duplicati is on a windows 2019 server system. thanks in advance.
Normally you don’t need to open the firewall for OUTBOUND connections. The default behavior of all OSes I’ve seen, Windows 2019 included, is to allow unrestricted outbound.
Is this server located in AWS or Azure? Note that they and probably other cloud providers block outbound port 25 traffic by default at the network level. Some ISPs do this as well. You’ll want to use port 465 or 587 depending on your email provider.
I would get PsPing to test TCP connectivity from the Windows 2019 machine to the mail server you are trying to use. Do something like this:
See if you get successful connections or not.