So we moved servers recently, and mostly this has been fine. The web was working for all domains, email was working mostly.. There were a few nagging issues but overall nothing major, except one. I could not for the life of me send email from my AT&T Tilt using my mail server. Previously I was sending through gmail which of course is setup to work with everything. Well, one of the problems with managing your own server is that YOU have to be the one to set everything up.
A look at some of the problems. First, no matter what I did on my phone, as soon as Windows Mobile 6 (WM6) saw that my server supported TLS it automatically issued the STARTTLS command. This is funny because I deleted my email profile and readded it 100 times both using SSL on outgoing and not using it. And no matter how I set it up, Postfix reported that WM6 was trying to use a secure login. Once I turned off authentication, it would no longer use TLS. Weird.
So we know I can connect to my mail server and we know now that TLS is working fine, but clearly something is wrong as I still can’t send mail. However I can send it from home just fine using Thunderbird. I have spent weeks on this folks. I’ve looked through every bit of postfix documentation, turned logging up to as verbose as it could go. All I know is that my WM6 device would connect, start a TLS session, and then disconnect. That’s when I noticed something.
Every single example I was reading was telling me to setup SASL to accept PLAIN and LOGIN mechanisms. Whether dovecot or cyrus sasl implementations, they all had the same thing in their examples. So I figured “What the hell?” AND IT WORKED! *cue fireworks*
So there you have it. If you are setting up your own mail server and need to have your Windows Mobile 6 device working with it, make sure to enable the LOGIN mechanism for AUTH on your smtp gateway. It will save you a whole heap of trouble.