I have had ATT DSL modem and router until recently ( Sept 12, 2012). On that day, the ATT installer changed me from pots lines to uverse voip lines and uverse internet. I can receive emails with no difficulty. Every time I start to send out an email using the email address firstname.lastname@example.org, the same as the emails I can receive, I get this message which says the server timed out. It ask do I want to cancel or try again. I try again and it yields the same result.
I had not idea I could only use an ATT email address to send out email. I have successfully sent out one email using a new email address they assigned me. However, I cannot use my email address of many years which is associated with a url owned by my company.
The ATT people made a few suggestions about SMTP name and ports. I used their suggestions. The same problem occurred. They then began to tell me to find the problem and get it corrected I had to purchase a $99 contract for technical support. I refused. Under protest, they told me my problem is that to use their internet with Thunderbird I would have to have a fixed IP address, but because I was new to ATT Uverse as a customer, I would have to wait thirty days to apply and then pay a monthly fee for a fixed IP address.
I am not paying more to ATT for anything else. I have been a long time members of Experts Exchange so I thought before I through out what they have grossly misrepresented to me as savings, I would see who out in the EE world might know what could be causing the problem, or know for sure that their notion of a fixed IP address is a required solution to get them more income for allowing service that worked on their DSL internet but is disallowed on their Uverse without paying a special fee.