Hi I have been using eM clinet for 4 years , all of a sudden I have been asked for a password and the error message is - Server says “[AUTH]Authentification failed”
Have tried my password and it does not work, help I cannot check my emails… Thx Mike 
There are two different errors? (Authentication failed / disconnected for inactivity)
Did you check with the provider for a solution? They may have changed something recently.
But some things you can check:
- If the POP settings are incorrect, you may get this error. There are specific port and security policy combinations so try these in Menu > Tools > Accounts, then on the POP3 tab:
Port 995 = Use SSL/TLS on special port (legacy)
Port 110 = Use SSL/TLS if available
- I am not familiar with your provider, but some like Gmail require setting access for less secure apps to allow POP3. If less secure apps is not enabled, you will get this error. Check with your provider and see if they have such a setting.
Also Authentication failed for a domain (non free account ) where it just suddenly stops if all settings have not changed, can sometimes also be ISP Billing related. Check with your ISP & Domain name providor if billing is all up to date.