Pine sends but says it didn't

[neath@psych.purdue.edu]

I've just done a fresh install of potato (from slink boot disks then
apt-get dist-upgrade etc).  I installed exim, and mail works (sending
and receiving) using /usr/bin/mail.

I installed Pine 3.96 and built a debian package.  I also compiled
the source myself to Pine 4.21 and 'hand installed'.  For both,
I get the same error:  When I send mail, I get a truncated message
that says mail was not sent.  However, mail was sent (and received
by the intended recipient); what is failing is copying the sent
mail to the sent-mail file.

An example of the message is:

[Mail not sent. Sending error: 2000-01-05 09:40:27 125rbv-0002VS-00 Exp]

I am then left in the compose screen.

Any suggestions?  

-Ian
--
neath@psych.purdue.edu