Yesterday a friend could no longer send mail from her W10 64 Home computer, using Mail for Windows 10. Her computer is protected by Avast! Free.
In the evening I had the same problem on a W10 32 Pro netbook, protected by Defender. This morning on my new W10 64 Home desktop, protected by Defender, the mail worked neighter. After I switched off Defender, I could mail. I switched Defender on again, but excluded the mail client wabmig.exe. Now I could mail!
I put Avast! Free on the netbook, but could not mail. I excluded the folder containing wabmig.exe and mail works fine again.
Thunderbird and Pop Peeper are not harmed in any way by this anti-virus false positive (if it is a false positive: still not proven 100%)
Does anybody recognise this problem? And my fix?