I will do my best to Explain the multiple issues I am now having in Thunderbird. For a while, I was struggling with the same issue that a lot of folks have had in which you cannot send emails from a particular email address in my case a frontier.com email address (........... @frontier.com). I actually have two email addresses with Frontier.com in Thunderbird and only one of them was a problem child. I could receive emails I could not send. Then, not too long ago maybe two or three days ago, the email I use for my website began malfunctioning (...... @armysurplusone.com. I cannot send emails from it, and when I try to receive emails from it I get this message "Sending of password for user ...... @armysurplusone.com did not succeed. Mail server pop.secureserver.net responded: Logon failure: unknown user name or bad password." When I worked with my website support, they directed me to Thunderbird support (I'm going to put the entire thread between Support and I down below because I'm not sure what some of it means) To add to this, I was able to send emails from ..... @frontier.com and simply add a "Reply to" line. now I can't send anything from that email either although it is still receiving emails. Any help you can give me would be greatly appreciated. Cornel Rasor Email thread to Bigcommerce support - read from top down: My email is not working. It is requesting a correct password. I have not changed the password. I have never had an issue with the email address (...... @armysurplusone.com) so I am completely unfamiliar with troubleshooting it. I use Thunderbird for my email. Since my email is not working, please contact me at ............ @frontier.com. Thank you, Cornel Thank you for your follow up with BigCommerce Support. Did Thunderbird provide the MX record information that needed to be entered on your site within a previous email? If so, you can provide the MX record information and I can add it to your site on my end. Are you able to receive the password reset email with the configured email forward in the Server Settings > Email & DNS Records area? Looking forward to your reply as we work to resolve the issue and thank you again for working with BigCommerce Support. Best Regards, Caleb Actually Thunderbird just set the email up without a hitch about 5 years ago when I started using it. I don't really know what the items you are asking for are. Also, I cannot receive anything at the ...... @armysurplusone email address. Cornel Thank you again for working with BigCommerce Support. I found historical MX records when looking up your site with the MX Toolbox and added them back within the Server Settings > Email & DNS Records area. I will CC the email in question to see if you are able to receive this email. I would recommend reaching out to Thunderbird Support for assistance accessing the account and requesting the "MX records and SPF record" needed for using email with their platform. Looking forward to your reply as we work to resolve the issue. Thank you again for working with BigCommerce Support. Best Regards, Caleb I will see what I can do in the next few days. I have no idea what the terms you are using mean but hopefully TB support will work with me. Thank you, Cornel edited emails from public and search/spam bots view as there was no need to post emails in public.