>> Google Chrome connects to the POP3/SMTP server on http
That's nonsense. "POP3" on "http" -- no such thing. Google Chrome -- is not a mail app, it's a web browser.
>> yet I can't ping/resolve the mail server from other apps
It sounds like you already tried apps like K9, Mail Droid, InnoMail, whatever...
And they're all unable to connect to this mail server, and it's isolated to your home WiFi.,
This tells me that the origin of this issue is not AquaMail itself -- but rather your home Internet provider and/or the WiFi router itself.
Sorry, this is not something I'll be able to assist with. Please try taking it up with your Internet provider.