We're working on a COTS product that includes e-mail integration and would like to test with several smtp servers. Which ones accept implicit SSL connections?
I would expect any servers that support SSL/TLS connections to support SSL only connections. If the server is listening on the the SSMTP port (465), this port is listening it should support only SSL/TLS connections.
Servers should not be SSL/TLS only on the SMTP port (25). The SMTP protocol is not SSL/TLS only. The protocol has been enhanced to support StartTLS functionality. Requiring TLS/SSL would severely limit the server's ability to accept email.
I would expect most servers listening on the Submission port (587) to require a switch to SSL/TLS before enabling authentication. This port should require authentication or a local connection before accepting messages.
Looks like there's a good chart you could use as reference on wikipedia:
http://en.wikipedia.org/wiki/Comparison_of_mail_servers
See the columns "SMTP over TLS" and "SSL" columns. It's not exactly clear but I think you're looking for ones with "Yes" in the "SSL" column.
I would expect any servers that support SSL/TLS connections to support SSL only connections. If the server is listening on the the SSMTP port (465), this port is listening it should support only SSL/TLS connections.
Servers should not be SSL/TLS only on the SMTP port (25). The SMTP protocol is not SSL/TLS only. The protocol has been enhanced to support StartTLS functionality. Requiring TLS/SSL would severely limit the server's ability to accept email.
I would expect most servers listening on the Submission port (587) to require a switch to SSL/TLS before enabling authentication. This port should require authentication or a local connection before accepting messages.