unable to authorize using SMTP

[محروم.كوم]

The mailing function returned an error while trying to send the mail.The following errors were outputted by PHP when attempting to send mail:


Warning: 535 Authorization to the SMTP server failed in [path]/includes/class_mail.php on line 607



I've been trying to use an SMTP service for my out going email. Normally I'd just quit and say it was the providers problem, but I haven't been able to send mail from both elasticmail.com or smtp2go.com I've had their techs confirm my settings and user/pass. Also I have confirmed I can connect on the port via telnet from my server. Everything appears to be completely fine, but I always get this result when I do a test email. Is there anything that you guys can think of that could be on my server that is screwing this up? thanks!!! __DEFINE_LIKE_SHARE__