sbc and att accounts fail to connect

[bbarrons]

I have been searching all morning to see if anyone has solved this but cant seem to find it. I have att DSL, want to use zimbra desktop as my email client. I can only get att and sbc to connect if I do not use ssl but I know that as soon as I start to send and rec this way I will bet a message from sbc telling me I need to use a secure connection. I also have Thunderbird setup and have no problems at all using the secure settings and getting it to connect. Am I wasting my time with this?
servers for att are pop.att.yahoo.com and smtp.att.yahoo.com
the yahoo connector does not work. I set them up as pop and they will work on port 110 and port 25.

I should add that up until now I have had a zimbra open source server setup that I now plan on shutting down. I ran it for 2 years as a test, paid for a static ip, and domain registration but I am now taking that all offline and want to just use my sbc accounts but I really love zimbra desktop as my client.
any ideas?
thanks
Bill