Several sites on my server are very old and receive lots of spam to unknown users.

I'm growing weary of the maillog filling up with lots of 550 "unknown user" error messages. However, I do not want to lower the logging level and lose other error messages.

Is it possible, within the sendmail configuration files, to set a specific error message to not log?

It seems if I could isolate the recipe or rule for that error, perhaps I could assign it a higher error number (higher than my log level) so it would no longer be logged.

However, after several hours of brute force google searches, reading sendmail help files and the sendmail for linux book, I have yet to find a way to do that.