limiting pop access to gmail servers ?

[Gleb Kurtsou]

On Mon, May 2, 2011 at 4:55 AM, George Sanders <gosand1982 at yahoo.com> wrote:
>
>
> We run our own (freebsd) mail server.  It's a pretty classic, old fashioned
> /var/mail/username setup.
>
> We have enabled POP so that certain people can pop their mail from us, and use
> gmail as their mail client.
>
> However, we have no other POP users ... and I don't want POP open to the whole
> world ...
>
> BUT, I suspect there are a LOT of possible IPs that google will use to pop mail
> from us ...
>
> Is there an authoritative list ?
>
> Anyone else blocking POP access to everyone BUT google ?

Didn't try it myself, just a wild guess. Hopefully google pop clients
use real ssl certificates signed by google to authenticate. Mutual ssl
authentication is hardly ever used, but still.

Setup pop over ssl and check for google certificates instead.

Gleb.