I have just started a new job and they use “Google Suite” for everything. I have always been used to using Outlook on my PC/Laptop. I started using eM Client about 6 months ago when I was made redundant. I have now tried to add my new company account to eM Client but get the above error.
One thing you can try is to completely disable your anti-virus/firewall and VPN, then remove the account from eM Client and add it again. See if there is any difference.