Why are you sending yourself email, when a copy of each email you send is already saved for you in your Sent mail folder? Did you ever consider that MobileMe considers email from yourself to yourself to be Spam, and therefore flags it as such; and that you've set your Junk Mail preferences to respect the flags assigned by your email provider?
Thanks for your reply.
To answer your questions:
I am not actually sending myself email.
There are two situations where email is sent to me from me.
Firstly whenever I send an email from my iPhone I receive a copy - this is useful, however it goes into Junk.
Secondly it is common practice if you are sending an email to many recipients to send it to yourself and put all the other recipients in the BCC field. (This is when you do not necessarily want all the recipients to know who all the others are.)
I wonder why, under these circumstances, would mobileMe consider email from myself to be spam?
That would not be helpful.
However I tried unchecking 'trust junk mail headers sent by my service provider' and it worked.
Not sure who my 'service provider' is - Mobile Me or my ISP - however thats what caused it
Now they are going to the Inbox.
Your service provider is MobileMe; it flags messages from you to you as Spam. So, as I suspected, you had Junk Mail set to respect that flags that MobileMe assigned to email. This is similar to if you had a Yahoo! Mail account: sending mail to yourself from that same account doesn't get flagged as Spam, it just never shows up.
Well, its not the default, it's just that email from the same person to the same person is almost always Spam, so that's how the filter is setup in Me.com. But you can bypass that, according to this Knowledge Base article from Apple:
Check the section titled 'Check your Junk mail folder and filters', and hopefully that will solve your problem.
Another reason for sending yourself email is that it is one of the quickest ways to get a file in and out of an iPad.
I have the same problem. Because it is flagged as junk mail, it won't show up in the iPad's inbox at all, when sending from my MacBook, but ends up in MacBook's Junk Mail box (as well as Sent mail box). Fortunately, one way around that is to go to the sent mail box on the iPad, and open the file from there (or move it to the InBox via the Edit--->Move command). Like the original poster, I'm using an email (Me.com) address from my Address book.