Integrating Domino into a home-grown iSeries app

We have a developer in a different branch of the company that is making
his initial foray into generating e-mail automatically from his
applications. His initial attempts have been successful, if limited,
using SNADS. However, one of his customers has a Domino server on their
iSeries and he's seeking information on interfacing his application with
their Domino server.

He's asked me because I'm the "resident expert" on e-mail in general and
because we have a Domino server on the iSeries. I have a vague
recollection of documentation about how to use the Domino SMTP engine from
an iSeries application, but it's been a long time since I did any
significant development and I'm drawing a blank. The error that he's
getting when he attempts this is CPFAF98, indicating that program QTMSFWD
detected a condition and ended processing on the message until the next
time STRMSF is run.

I'm expecting that there's documentation out for this sort of thing, so if
you can point me toward where, I'd greatly appreciate the push.

Thanks in advance,
Patrick