I have setup a Windows server 2012 R2 SMTP server and it's working fine, accept that is not using the correct certificate for the outbound connection, which is een problem because i need it for my office365 (exchange-online) connector to identify itself so i can relay emails.
In the personal certificate store on the server there are two certificates that are almost identical, accept one is .local and the other one .nl. Without any reason its using the .local certificate to communicate. The only way to force the smtp server to use the .nl certificate is when i remove the other certificate or if i disable its client authentication function. The fully-quilified domain name in the advanced delivery tab is the same as the certificates subject name and I'm seeing the correct date under "access -> secure communication".
I'm using port 25 for outbound connections and TLS encryption is enabled.
Does anyone have an idea how i can force the smtp server to use the correct certificate without disabling the other one?
I already tried to use "netsh -> http -> add sslcert" to force port 25 to use the certificate but it doesn't work. Probably because its using starttls after the connection is made.