Mail Search function shows inconsistent results


Can anyone tell me why it is that when I use Mail's search function for a particular email address (in Trash folder, for example), the results don't always include all the entries on my system? ie. There is a particular email in my Trash I was just searching for, and I knew the email address to look under but the search results did not include it. When I did a manual search, message by message I found it. I've noticed this happening a lot.
Are you searching using the name or just the address? Using the name works well.
Have you used Rebuild? Go to Mailbox menu and select it - the last item on the pull down menu. Depending on how many emails you have will depend on how long it takes. Then give search a try.
Did you mean that the rebuild didn't function - or, that you still have the same problem?
Maybe you don't have your account selected when you try the rebuild.
If you want to monitor what DOES happen, go to the the Window menu in Mail, then Activity, which will show the rebuild processes while they are happening.
And, nothing much will be visible even there, unless you have more than a hundred or so emails in that account, as the activity flashes by pretty quickly.

As the Mail search would depend on Spotlight, you might also rebuild your Spotlight database. THAT can take several hours to complete, again depending on the amount of files on your system drive. The common method here: