Error - smtp not connect into server

Reinstalling eM Client after pc crash, not related issues.
Cannot setup new mail account - error message states cannot connect with server. Used the “Diagnose” function. It also has the same issue. Contacted the provider - Tech support states nothing wrong with their end, and can log into the providers site with username and password - no problems. Thanks

As a test, can you completely disable any anti-virus, firewall, proxy or VPN, then try again.
Sometimes even restarting your router may resolve this.