Thunderbird can not connect to either of two email servers. It is not an account settings issue. I have not made any changes to Thunderbird, my system, nor my accounts. They worked the previous day and for years prior and then simply did not work this morning. Thunderbird simply continues to try and connect and never times out, never asks for a password, never gives any error messages. I have already tried the safe start, turn off virus, turn off firewall, reinstall Thunderbird, try alternate Internet providers, etc. to no avail. I am using Mac OS el Capitan, Thunderbird 52.2.1. Again, no changes and suddenly I have no access to two different server accounts. The settings have not changed. Thank you. Chris