Useful on how to use Spotlight on iOS. For example:

Flagged june 2013
Searches for all flagged messages from june 2013, as well as for messages containing these words

Unread last week from:.com
Searches all unread messages from last week where the sender’s email ends with .com, as well as messages containing these words

Vip read yesterday
Searches all read messages from contacts marked as VIPs, as well as messages containing these words

to:appleseed monday
Searches all messages sent on Monday to a contact named “Appleseed”, or an email address starting with appleseed, as well as messages containing these words