How do I turn on SMTP Authentication?

[time4e]

I have Roundcube configured for my personal email server powered By Iredmail. Recently I have been getting bounce back messages from Google (http://support.google.com/mail/bin/answer.py?hl=en&answer=10336) long story short my IP address that points to my domains DNS record falls within ranged listed on the PBL according to http://www.spamhaus.org. The solution is to configure my mail client for "SMTP Authentication" per http://www.spamhaus.org/pbl/removal/. My question is how do I configure Roundcube for "SMTP Authentication"?

Thanks,
-Tim

[JohnDoh]

are you sending mail via google's smtp servers or sending mail via your own smtp? if its your own smtp then smtp authenticaion wont help. smtp authentication is way of veryify that a users is allowed to send email using a particular server its got nothing to do with convincing a recipient its not spam.

to answer the question. look in the main config file and you'll see a set of options like smtp_user, smtp_pass.

[time4e]

JohnDoh,
Thanks for the reply. I am using my own SMTP server. I have no trouble using my email server with the Mac mail client which was configured  to use a TLS certificate. that's the only thing that I see different from roundcube's configuration. Can roundcube be setup to use TLS? Why else would email be bounced back when sending through roundcube and not another email client? I have contacted my DNS provider, No-IP and they have suggested I use their Alternate-Port SMTP service.

Thanks.
-Tim

[JohnDoh]

Why else would email be bounced back when sending through roundcube and not another email client?

Thats a very broad question and I'm sure that I can't think of all the possibilites. Send test emails from both systems and compare what your SMTP logs say happened and the message headers also see if you can find out from Google why they thought it was spam. That should give you a place to start at least.