When using Apple Mail, you can search for text in all mailboxes or in selected mailboxes. You can search in the "From" or "To" address fields, the subject line, or the entire message (which includes the address fields and the subject line). Searching entire messages also searches image files and attachments. You can also search within an e-mail document by clicking Edit > Find (or Command-F), entering the text you want to find and then clicking "Next". If you select some text and move to a different part of the message, you can jump back to the selected text by choosing Edit > Find > "Jump to Selection" (or pressing Command-J).