When trying to sign up on some sites my att email address says invalid. I have no trouble logging into email, facebook, banking. This is mostly on new sites I am trying to sign up on. This does not seem to happen on IE.
This happened on the Virgin mobile website, as well as the Indeed website when trying to apply for a job. Have had this happen other times as well.
Wšykne wótegrona (2)
Sites usually don't check whether your address is alive, they mostly check the format. For example, username@mymailsite.com (has @ and a valid domain).
Do you use any add-ons that help fill out forms? If so, maybe clear your email address in there and re-enter it to make sure it doesn't contain unexpected characters.
BTW, what version of Firefox are you running?
Wót jscher2000 - Support Volunteer změnjony
This issue happens more often than not now. I am typing it manually. I am on Firefox 11.0. This is really annoying. I have started using my hotmail address rather than my att as it is often not recognized.