Yes, this sounds plausible. You don't happen to remember if it was
a Lotus/cc:Mail or a third party product?
I managed something like this for MS mail at one point.
On Wed, 07 Oct 2020 17:22:27 +0200, Gavin Scott wrote:
These may all be dead short-circuited neurons, but
IIRC there was a
cc:Mail Gateway or Internet Gateway special product you needed to buy
that would run on a dedicated PC box (under DOS?) and would talk in
turn to your cc:Mail post office server and the 'net to exchange email
messages in and out. It had the semi-annoying habit of retaining
plaintext copies of all incoming or outgoing messages (one or the
other, I forget which). There was also some non-trivial configuration
setup required on both the Gateway and cc:Mail servers to explain all
this to cc:Mail. I think there was some sort of route name or gateway
name specified with email addresses, possibly with a comma after the
internet address, but like I said those brain cells are almost gone.