Does your anti virus have some sort of "password vault" ?

Try disabling the scanning of email in that anti virus and see if that helps.

is your password more that 8 or 10 characters long. While I have no information on Cox there were issues with Hotmail a couple of years ago that the password rules for web pages and mail applications where different and passwords longer than 8 characters worked fine in webmail and failed completely in a mail application.

Thank you Matt. I reduced my password to 8 characters (min. for Cox) but that didn't work and I couldn't find where anti virus is scanning so couldn't do anything with that. What I did do was simply create a new account and that got the email going again. I still have the "invalid password" message when I open TB but I think I have to remove one of the old accounts to get rid of this. Will create a restore point before I do this in case I screw it up. Thank you for your help :)

There are a few people posting with issues with Cox.

Thank you Airmail but I really have no issue with Cox. My email can now receive new mail and send but I am still getting the "invalid password" every time I open the app. How can this be? If I am receiving mail the password must be valid. I am at a loss as to how I can fix this! I have looked at my profile but there are so many folders in there I wouldn't know where to begin if the problem is there :(

Have you set up a calendar? Most have passwords for the server, like Google and Yahoo. What about contact sync using an add-on. Again they use passwords. Passwords are also used for chat accounts. so you are not just looking at mail passwords. It really depends on what you have configured Thunderbird to connect to.

My wife is having a similar problem. If she presses cancel, she can send but not receive. Looking at Tools | Options | Security | Passwords | Saved Passwords clearly shows that Thunderbird already has the correct password. But....my provider is Comcast.

Wrote in another thread that I had a trojan on my computer that created the exact same symptoms for Outlook. Trojan sent my username and password to a hacker in Europe.

@[caliRoll] If the above information does not resolve your issue, please consider creating a new thread containing the specific details of your issue.

Doing so will allow the Mozilla volunteers to give you solutions that are more helpful to you. This may help them to solve your problem faster and more efficiently.

Please, feel free to post the link to your thread on this thread for volunteers interested in assisting you.

Thank you.