I have 3 different email accounts on Thunderbird. All was working perfectly yesterday. Today, none of the email accounts can connect with their respective email servers. (Two are Verizon/AOL and one is gmail.) I have tried various fixes with no joy. At this point I give up. My email is very important in my life (I'm 81 years old) and Thunderbird is simply way too hard to fix with non-existent help. (Your Community help line is a joke unless you have technical knowledge. Nothing ever quite fits the problem so it is no help at all.)