boy, am I steamed!!!...

[sgtcarl1]

My internet provider is Suddenlink. So my e-mail address is @suddenlink.net. I would switch to a different e-mail handler, but wouldn't I have to use another e-mail address? The error message appears in a pop-up window as soon as try to send it. I have no problems receiving e-mail. I have re-checked the e-mail settings so many times , I can't count that high. Suddenlink can't find the problem, either. All advice is greatly appreciated, and I am considering all options suggested.