Thank you, thank you, THANK YOU!!! I have been fighting with this issue for DAYS! And you are right...AT&T has been NO help whatsoever. All the settings info on their online support pages is bogus! I don't know how you discovered the correct settings (and I wonder for how long they will work?), but BLESS YOU for managing to figure it out.
AH HA!!!!!!.... Sooooo ATT is making non-public changes "Again" Its funny how U-VERSE will send me a postcard everytime about changes in programming OR new channels or numbers changing, but when it comes to I.T. changes... no one has a "CLUE"
My settings have always worked and suddenly just stopped working... I've adopted the updated settings and I CAN SEND EMAIL VIA OUTLOOK 2007 again...
Note to ATT Tech Support... please inform your technicians to stop telling clients that this is a Microsoft issue... because its not.
If you like... i guess you could blame in on Gremlins making changes during the night?