[whpalmer4]

Okay, here are some things to check:

1) your message has to be plain text, not rich text.

2) turn off any archiving -- that way, if the mail stays in your mail inbox, you know that the rule didn't do anything with the message

3) make sure the address you are sending from is on the list of valid recipients

4) send a message that doesn't have any special characters as a test to your "user+omnifocus" address. It should end up in your OF inbox with the message text as a note if you've got the things above correctly set. Once you know that you can successfully get a message delivered to OF, you can start tinkering with the various characters to route things to projects, contexts, dates, etc. Prove that you can walk before you try to run, so to speak.

For clipping, see the OmniFocus help command and enter "clipping" as the search string. There's a nice page of info, complete with pictures.