When I send a message using telnet/PHP, and I add extra headers ending with CRLF, GW8 GWIA translates that CRLF into LFLF, making the header part of the message. This is especially annoying in multi part MIME (HTML) mail, and results in almost unreadable mails.

According RFC822 (section 3.1.2), headers are supposed to end with CRLF. See Command sequence: ----------------- mail from: f - Bart for a example case.