We have setup a windows server virtual SMTP (under IIS6 manager). In the SMTP settings, TLS encryption is enabled, fqdn field is "sharepoint.mycompany.com".
In the server's cert store "personal" folder we have the certificate "sharepoint.mycompany.com". The real fqdn of server is "server01.testdomain.com". By some reason we cannot apply cert for testdomain.com. By ping "sharepoint.mycompany.com" it is resolving to our server's IP.
We need to send email by relay to our company's public SMTP server. The SMTP server admin said they don't care the cert name as long as there is a cert issued by our company's CA (which we already have).
After some tests, the connection is established. However we got "No client certificate presented" respond:
My question is, how to test or configure the certificate? In windows virtual SMTP manager, there is no place to setup which certificate we are using. Also, I heard that OpenSSL program must be used to request a standard cert. Our cert was generated with IIS7. I am not sure whether it is the cause because the error message is not complaining the format or validation of cert.
Thanks for advice.
openssl s_client -connect sharepoint.mycompany.com:25 -starttls smtp
8964:error:0200274D:system library:connect:reason(1869):crypto\bio\b_sock2.c:110:8964:error:2008A067:BIO routines:BIO_connect:connect error:crypto\bio\b_sock2.c:111: `connect:errno=0