I am trying to set up 87 rules for a specific mailbox. Problem is, I get an error message stating there are too many rules. Is there a limit to how many rules a mailbox can have? If so, can this limitation be manually expanded?
The limit in Exchange is actually a size limit rather than a number one. Exchange allocates 32K for storing rules. Typically that works out to somewhere between 40 and 50 rules per mailbox, but it depends upon how large or complex the rules are.
There is no workaround for that, that I'm aware of. Your best bet is to see if you can combine/economize any of those rules in an effort to squeeze under the limit.
The only other option I can think of is to consider writing some server-side script (in VBScript) that might accomplish some of the tasks you have in mind. But unless you're a Visual Basic programmer, that isn't the easiest solution.