I can't find a particular message in my mails using Apple Mail on Mac OS X Lion. It connects to my mail server by IMAP.
I select my inbox (the one I want to search)
On the top right corner I have a search field.
I start typing the string I want to find.
It displays no records found, but I'm absolutely sure that this email exists. I've found it on my webmail interface.
If I restrict my search to "Subject", I can find some of those messages containing that string in the subject. If I switch to "Entire Message", that same message can no longer be found.