SMTP error

[Mhojo_NZ]

I have V16.0.4.493 on an active Enterprise licence.
I recently migrated my 3CX instance from an old Windows 2008 server to Windows 2019 using the backup restore method.
On the previous server I had a local SMTP relay running and had no problems with outbound email.
On the new server I am attempting to use a cloud hosted Exchange server.
When I set the credentials I get the following error:

• An error occurred while attempting to establish an SSL or TLS connection. The SSL certificate presented by the server is not trusted by the system for one or more of the following reasons: 1. The server is using a self-signed certificate which cannot be verified. 2. The local system is missing a Root or Intermediate certificate needed to verify the server's certificate. 3. The certificate presented by the server is expired or invalid. See https://github.com/jstedfast/MailKit/blob/master/FAQ.md#InvalidSslCertificate for possible solutions.

We do have a static external IP but in 3CX I have to set the external IP the same as the interface IP as our SIP trunks come via a private network. If I don't do this clients can't register as no inbound ports are open on the firewall. So... on our SSL certificate is a private IP, not the public one.

I can use Gmail to send emails successfully.

Any pointers would be appreciated (or I will just go back to my previous workaround).

 

[cobaltit]

The error message seems pretty self-explanatory. I'm not sure why started talking about external IP, static IP, etc as the error message doesn't state anything about IP address, just the certificate validation. You just need to confirm the certificate used on you SMTP server per the error message or uncheck 'Enable SSL/TLS' if it's not required. Or just use the 3CX SMTP