Hi, i’m installing mailcow on azure VPS.
Everything works fine, but my emails dodesn’t arrive.
I have this in queue manager:
How to fix that? 🙁
Outbound SMTP connections that use TCP port 25 were blocked.
Apparently Azure blocks outgoing SMTP.
So mailcow won’t work on Azure? or I can change port 25 or smth..
It’s not a matter of “mailcow works on Azure”, as SMTP is a standardized protocol using TCP/25. It’s not unique to mailcow.
Technically you can change the SMTP port, but no other mailservers won’t. So you can basically only send mails yourself then.
Hetzner doesn’t block 25 but your email may go in spam on MS and Google
Digital Ocean blocks 25 by default but you can ask to have it unblocked
AWS does not block 25 but they have strict TOS, they will cancel your account if you spam.
Physical server on decent ISP or in colo works very nicely.
You could also ask Microsoft to remove the limitation: https://docs.microsoft.com/en-us/azure/virtual-network/troubleshoot-outbound-smtp-connectivity I once tried to contact the support about this and they allowed me to use port 25 after a few hours.