Before you remove ZA, let's check another easy setting first.
I haven't installed version 5 yet, but on my system, I have my Gmail POP set up for port 995 in TB version 3, with just my User Name, not entire @gmail.com. See first image.
And for the IMAP account, port 993, but entire email address in user name. My SMTP settings are below as well.
Hope this helps.
Marc