[syslog-ng]Eliminating certain keyword from the "all" directive?

[Stephen C Burns]

Hi all,

I have a question regarding the redirection of certain log messages to
files.  I currently have the "all" directive sending every syslog
message into /var/log/messages, via:

destination all {

                  file("/var/log/messages");
                };

And that is great, except I don't want my mail messages getting sent
into the messages file as well as this takes up a lot of space.

So I basically need some way to say "send all messages except for mail
messages into /var/log/messages"

Is there such a way?  Thank you for any help!!