For the past month, I have had two or three certain email addresses/domains, not receive any emails I send. I have been sending to these people for several years with no problems, and all of a sudden they are not receiving anything I send from thunderbird. However if I send them an email from my phone or webmail (my email is gmail based account), the email is received. When I send the email from thunderbird, it also does not bounce back or anything, so I don't even know if there are more people that aren't receiving my emails. The two addresses that aren't getting my emails, it's not just two specific addresses, but the entire domain isn't getting them. For example, I realized that there is a certain law firm that I deal with and not only was my contact at that law firm not receiving it, but nobody's address from the entire law firm was receiving the emails. Same thing with my accountant, no email address from his office was receiving my emails. However, again, if I send using webmail, it's fine. I really like using Thunderbird and have used it for the past ten years, and I really don' t want to have to switch to something else. Can someone please help ASAP. Thanks,