No connection to SMTP - POP3 - IMAP-Server

A number of users have complained that they are unable to connect to our mail servers even though they have entered the correct access data and server name. This problem is almost always associated with a locally installed antivirus protection software that monitors the Internet connection and (for whatever reason) blocks the connection to our mail server.

Check to determine whether a local firewall or other protection system may be blocking your access to the mail server.