After updating to version 31.5.0 Thunderbird some of my imap server accounts will not function. They do on my other machines (not updated). Getting mail or sending mail I get this message: "checking mail server capabilities .." It will eventually time out. SMTP settings have not changed (using port 25). I have "allowed" Thunderbird.exe in windows firewall. Using Norton Anti Virus. Have tried disabling temporarily. Am able to access smtp.googlemail.com (different port). Thanks in advance for any advice.