Solved The SMTP server does not support the STARTTLS extension.

[jgoz]

Hey Gang-

This is on a new system I'm installing, Have never had an issue- This is using the 3cx SMTP server. When I switch to my Office365 account credentials, works just fine. V16 16.0.5.454 I also have this version on a separate server, and it works just fine on the 3cx SMTP server. Just looking to see where I should look.

Thanks

 

[jgoz]

Sorry all- was an issue with our firewall not allowing Outbound on port 2528.