Hello, @ahmaddanial.
Since this is a custom SMTP and we do not have any related documentation on customized SMTP, can you please explain a little better on what you mean by this statement?
I’m sorry, this expression was not good. And I was misunderstood about SMTP authentication and Connection Security.
Testing mail with settings pattern 4, mattermost said success:
No errors were reported while sending an email. Please check your inbox to make sure.
Connection setting of Mail server is plaintext not encryption, so right setting is pattern 1. But mattermost say “error”. I thought judge of “Enable SMTP Authentication” is reverse, because when mail server say “250-AUTH LOGIN PLAIN” to mattermost, mattermost say “QUIT”. So I tried other patterns.
But, any patterns are mattermost don’t send plaintext password to mail server.
After that I found If you fill in SMTP Username and SMTP Password then you must set Connection Security to TLS or to STARTTLS is written in documentation.
Is there no way to send plaintext password?
Additionally, can you share more insight on this internal mail server? Is it built from scratch on your end?
Mail server built based on this “m-FILTER”.
Would you also consider any of the supported SMTPs listed in the documentation for testing purposes?
Not immediately, I’ll plan to build test mail server with general settings as written in documentation.