Thread:Project:Support desk/problem to send email (smtp) to exchange server/reply (3)

Ah, I think I didn't specify well where the problem is ;)

It's the mail server (exchange) the one that doesn't support Digest-MD5, CRAMMD5, LOGIN or PLAIN authentication options. Those are the only authentication options that PHP supports.

You don't need to change anything on PHP, because it will automatically choose one of the authentication option on that list (Digest-MD5, CRAMMD5, LOGIN or PLAIN), the first one that your mail server supports.

You have to enable at least one of those authentication mechanisms on MS Exchange to be able to send emails from PHP using that exchange server. Otherwise you'll have to use another mail server like gmail.