I can successfully send / receive WEBMAIL using my att.net email identity.  I have spent one full day (and substantial phone time with AT&T techs - pleasant, but NO helpful advice other than to sign up for their pay-for tech advice service) trying to configure an external PC based email client to access my ATT.NET account.  I have carefully downloaded and super-carefully followed ATT.NET advice for 1) Thunderbird 5, 2) Eudora 7.1, and 3) Microsoft Live Mail on my Vista 32 PC.  Absolutely nothing works.  Having searched many blogs, I see that Yahoo.com email can NOT be accessed by an outside client - it is a web based service only.  I suspect that because AT&T now uses Yahoo.com for email, AT&T also can not be access by any standard email client.   This is a huge problem for me - I view cloud based (web based) internet email as inferior to my downloading email to my PC, backing it up, organizing it, and managing it at the PC level.   FURTHER: I was told now that I have an AT&T 'GATEWAY' device (AT&T's combination modem / wireless router) that device must remain on my home's carefully ethernet cabled system to run the TV --- and can not be removed or my AT&T UVerse TV system will stop.  Thus, if I return to my earlier ISP (Comcast), the Comcast-provided cables that AT&T took over apparently can NOT be used by Comcast ... I will have to have my house double-wired for AT&T TV and Comcast-Internet.   My questions: 

a) HOW CAN I ACCESS ATT.NET EMAIL USING ONE OF THE ABOVE EMAIL CLIENTS?

b) IF I MUST RETURN TO COMCAST FOR EMAIL, MUST I ALSO DUMP U-VERSE TV TO USE EXISTING COAX CABLES to return to  Comcast Internet+ email?

Thank you, in advance ...

ps: among the MANY AT&T and related pages I looked at are

http://www.att.com/esupport/article.jsp?sid=KB401568
http://www.att.com/esupport/main.jsp?ct=9000722

http://www.att.com/esupport/article.jsp?sid=KB401738

http://www.att.com/esupport/article.jsp?sid=KB401570

and more....  The suggested answers ... don't work.