I have the same issue on a newly installed avast! for mac.
when I try to add imap.gmail.com, I get the error "Error verifying mail server"
and the same for imap.googlemail.com
**** HOWEVER ****
When I then try adding my corporate email server, that verifies OK *and* then both it *and* the imap.gmail.com server
that was reportedly not verifyiable shows up with IP addresses in the list.
**WTF**?
So now the unverified imap.gmail.com is listed as if it had been verified. Thus avast will now think that server
verified even if that was not possible?
(or is it that it was in fact verified, but it just failed to be added to the list and the wrong error shown?
In either case, I have *NO TRUST* in that anymore...
Trying to verify it again afterwards still fails.
This is with Avast 7.0 (37781)