Uverse is blocking my outbound SMTP email

One more dumb question:  Does the user have to have an email client installed with the Bellsouth email account set up before the email send code will work?  Or, does a laptop know the smtp credentials simply by virtue of its access to the internet?  I assume the latter is correct. 

If I take my laptop to the home of a friend whose Uverse is blocking port 25, I cannot send, as I am connecting to the internet via her bellsouth wifi.  She can take her laptop to her office which uses something other than Bellsouth, connects to the internet over their wifi, and sends without a hiccup.  So, I am confused, as it doesn't seem to be depending upon the setup credentials on her computer.

You do not need separate client software if your software performs those functions (i.e. makes the SMTP connection and speaks the SMTP protocol to the host).

However, if your client performs those functions, then that means that your software must:

1. Connect to a port (other than 25 if blocked)
2. Create an SSL tunnel if required by the SMTP host/port you're using
3. Perform authentication if required by the SMTP host/port you connected to

i was recently switched to uverse as i was talked into geetting the new fiber optic modem. been a nightmare but i am finally online

however uverse is blocking my outgoing smtp server

my outlook use to work perfectly and the smtp setting was : outbound.att.net

now i can't send out anything - it sits in my outbox 

any help wouyld be great - like the correct outgoing smtp server setting

thx

steve

well after being hung up on twice and never called back by the tech support people and having the live chat freeze up and that guy never calling back i had the bright idea to look at my smart phone ( the phone is smarter than the people i was dealing with) and looking at the settings on my email there

ta da - all i had to do was switch my outgoing smtp to port 465 and the security to ssl/tls (instead of auto) and wonders never cease my outlook is back working aand sending emails again

this was with the smtp server set to : outbound.att.net

amazing - i know diddly squat and am as far from a techie as you can get - but i guess common sense and a little logical thinking still works.. thank you to those who replied and for the chats i saw previously of those with the same issues - you gave me the courage to muck around and dyi..by the way a little advice to any that try my way - make sure to write down what you had before for settings - it will give you a little confidence that you can undo your own goof ups - lol

JerrerMC, what procedure can be followed to get port 25 unblocked?  How difficult? Is it even possible?  I understand why it is blocked, but I don't have anything nefarious going on--just want to be able to send emails to 180 little old ladies who have signed up for a golf tournament!