I am attempting to install and configure Roundcube. I have used many posts here the forums to aid so far. My server is a Debian Lenny 64 Install using the Perfect Server install on this site. I further installed dkimproxy which signs outgoing emails with DKIM and DomainKeys signatures. Emails are signed using incoming port 587. As part of the Perfect Server setup, Squirrelmail is installed. In the Squirrelmail configuration, I changed the SMTP settings to use port 587 and all outgoing emails were signed as intended. I have now installed Roundcube and attempting to replicate the success I had with Squirrelmail. I changed the SMTP port to use 587. However, Roundcube cannot send emails. If I change the SMTP port to 25, emails are sent but are not signed by dkimproxy. I first looked to the Roundcube error logs. There were entries that said something to the effect that an invalid response was received. I dug further and found the error message below in the syslog file. I have sanitized the error messages shown below: Code: Jul 20 16:21:42 server postfix/smtpd: warning: SASL authentication failure: cannot connect to saslauthd server: No such file or directory Jul 20 16:21:42 server postfix/smtpd: warning: server.example.com[192.168.XX.XX]: SASL LOGIN authentication failed: generic failure Any ideas why this would work with other email clients and not Roundcube? I have tried the Roundcube forum as well. But upon posting the error messages above, the response I received is that it is not a Roundcube issue. Any help would be appreciated.