my email is being rejected as not existing but have had for over 10 years

First of all, can I gently suggest that when writing about "email", please consider adding words such as "address", "message" or "account" . Otherwise the reader has to parse what you're trying to say and infer the context for each appearance of the word "email" by itself. Thank you. ''nancyfbarton [[#question-1161828|said]]'' <blockquote> My email '''address''' is being rejected as not existing but have had for over 10 years I have checked with my cable provider and they are able to send me a message and I can return one; however I was opening an account with Allianaz and they said my email '''address''' did not exist. Also when I send an email '''message''' it will say it was not sent to the sent folder but in a few minutes it is in there. </blockquote> I think this hangs on the "in a few minutes" - this suggests that your incoming email server is a bit slow and the Allianz server is just a bit impatient. It doesn't get a reply within the timeframe it expects, so reports your server's lack of response with the incorrect inference that the account doesn't exist. In some cases where we have trouble in Thunderbird, working directly through the email provider's website may help, but I doubt this will help in your case. I think this is an issue with the responsiveness of your provider's server, and the way you choose to access it won't affect its speed as seen by external connections. Your cable provider's server may have just been busy, or operating at a limited service level at the time, and you may find it works next time you try. If your server is consistently slow, then I'd consider setting up a separate email account, on another server. Having multiple accounts is useful to check how things are working; you can send from one to the other. If any one server breaks down, you have a fallback. Services such as gmx and Gmail allow you to register other providers' email addresses, so you can continue to use your preferred addresses if obliged to use your fallback provider. You could also look to see if you can contact "Allianaz" by some other means to explain the problem. A human help desk operator could probably override the automated check that is currently failing, and enter/validate your email address manually. The bottom line is that there is probably little you can do to fix this by yourself.