What happens when rt-mailgate can't submit a ticket?

We had a problem here over the weekend where apache ran into a memory
limit, and rt couldn’t take any connections from rt-mailgate.

I pass mail from procmail to rt-mailgate, and rt-mailgate was failing
with errors like:

An Error Occurred

500 Server closed connection without sending any
data back

Does rt-mailgate try to save those to disk anywhere, or are they just lost?

Thanks,
Graham

rt 3.4.1, freebsd 5.3-RELEASE-p9