Gary/Greg,
Hadn't gotten around to doing the nuke and re-install etc and have simply been forwarding emails to my BB email address (which is the workaround suggested earlier in this thread).
Anyhow, after one month since the problem first occurred, lo and behold, as of yesterday my 8310 suddenly slipped out of 'idiot mode' is now receiving all emails.
Nope, no soft or hard resets, deleting and recreating email accounts etc, or no deletion or installation of third party software etc that may have triggered 'normal behaviour'.
Yes, happy that it's now working fine, but from a problem determination POV this is a little unnerving.
Anybody else out there with a schizo 8310?