SMTP Authentication not working with special characters like "§"

[geri777]

My SMTP Server requires a password which looks like "6Xcf§5cXR6zB%"
When I try to connect I get the following error:
SMTP connect() failed.

When I change the server's password to any password WITHOUT an "§" (section sign), everything works.

I am using version 6.9.1 which is the latest version at the moment.
I am using SMTPSecure = SSL

[Synchro]

§ is not a 7-bit ASCII character, and so it's not possible to use it unless a system supports SMTPUTF8, which PHPMailer does not. That said, LOGIN and PLAIN auth schemes base64-encode the password string which should insulate it from that, but that will still rely on the unencoded auth string being in a non-ASCII charset, such as ISO-8859-1, which you can't select from the client end, so I doubt it will work anyway.

I suggest setting $mail->SMTPDebug = 4 and look at the exact text that is being sent.