Errata

When using mutt the Organization field is ignored.

There are several limitations when using pine and fancier mailto:
urls.  Message bodies are treated as attachments.  Any commas in
subject, cc, bcc or organization will cause problems.  The python
script converts any commas in those fields to underscores before
passing them to pine.  The shell script just blindly passes commas to
pine, which then drops everything following the comma until the next
valid header starts.

I don't use dtmail, so the provided support is untested.  Feedback
from dtmail users is welcome.

I don't use VM, so the provided support is untested.  Feedback from VM
users is welcome.

I use tin infrequently, so the provided support is poorly tested.
Feedback from more frequent tin users is welcome.

My experience under Communicator 4.6 is that "File:Send Link" does not
work, but "File:Send Page" sends a link.  "File:Send Link" does what
it is supposed to under Navigator 4.6, so I think this is probably a
Netscape problem.

Under Netscape 4.6 and earlier, if you enable news functionality,
clicking on a news: url calls ShowMailBox() rather than
HandleNewsUrl().  I believe this was fixed in Netscape 4.7.

Once again Netscape doesn't seem to be following their own API, and
I'm not sure how to work around this one.  Under Navigator 4.6 none of
OpenMailSession(), CloseMailSession(), RegisterMailClient() and
UnRegisterMailClient() get called.  This makes it rather hard to clean
up temp files properly.  That wasn't much of a problem when we were
just creating a single file with the same name over and over again
(that scheme has lots of problems of its own though), but now we are
actually generating unique filenames for each instance.