sendmail, full names and yellow pages

[Tim Chown]

We have a Sun 3 network under 3.5 running generic sendmail and have the
following problem.  When you send mail from the server, the user's full
name is always inserted in the From: line correctly, but when sending from
any of the clients, the From: line just has the plain user id.  We are
running yellow pages and I'm mystified as to why the full name is not
inserted.  Is it a known bug, or might something not be configured
properly ??

Any hints/clues would be gratefully received,

	Tim Chown
	T.Chown at ecs.soton.ac.uk