Whilst I don’t use eM Client. I use Thunderbird, but don’t collect my gmail using it, I get notifications on my mobile phone for new emails on my gmail account. So I can’t be any practical help.
A screenshot of the error might help determine why for others using the same eM Client and gmail.
The last post was correct. Leave the MAIL SHIELD turned on, but uncheck (disable) all of the other options.
If you are using Google mail (gmail), they scan your email for you.
GOOGLE doe NOT allow anyone to send executables (.exe, .com, .bat. etc…) in their email.