Updated to eM Client 8 and now it won't connect to my Gmail Account

try this fix…it worked for me

Open the registry (regedit):
Go to
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\SecurityProviders\SCHANNEL\Protocols\TLS 1.3\Client
and set Enabled to 0

I do have the same problem with another email service (siteground)

Also if you are having problems with connecting to Gmail from EMC (apart from any Firewalls / VPNs etc that might be blocking), make sure you have "allowed EMC access to your Google Account). See this thread below.
Problems with Gmail account login - Mail - eM Client