Now that you have 25GBs of email storage, you may need some help finding that one email message about that staff meeting sent 2 months ago. With labels and filters, you can set-up a system for categorizing, moving, and finding messages you have organized. With search, you can find messages wherever they may live in your inbox - labels, deep within your Inbox, or archived away in All Mail...
You can use search in Apps mail the same way you'd use Google Search, by entering a word (or multiple words) that appears anywhere within the message you want to locate. If you're looking for a message that contains the word testing schedule, simply type testing schedule in the search field and press the Search button. Your results will be displayed with your search terms highlighted in yellow.
Please note: Apps mail search doesn't recognize special search characters like square brackets, parentheses, currency symbols, the ampersand, the pound sign, and asterisks. It also doesn't recognize partial or similar matches, so a search for travel will find travel, but not travels, traveler, or travle.
Reference Search Overview