| | Message Rules
I have used two products. Notifire allows certain actions to be taken when a message is received. It is based on a contact name (or you can set up a custom contact - an address that is NOT in your contacts). The choices of what to do when a message is received is essentially how you want to be notified (popup message, different tunes, etc.)
The other product (and the one I am currently using) is Message Alerts. This is very much like setting up rules in Outlook as you can specify certain condtions such as from, to, priority, subject contents, body of message contents, and so forth. You also have more control over what actions you want to take. In addition to seelcting different tunes based on the rules, you can delete a message, forward it, auto-reply to it, and so forth. These rules apply to e-mail and SMS messages. It also has a spam "rule" built into it. If you get a spam message you can click on "Spam Rule" in the menu and automatically add the sender's address to a list. Future messages from this sender will be deleted. Statistics are maintained for each rule you generate which is a nice way of justifiying the cost (which I think was in the $15 to $20 range).
I would vote for Message Alerts. I purchased 9and still have) Notifire before Message Alerts was available. Both can be obtained through Handango. Hope this helps...