In embodiments, mobile devices request and utilize recipient caches. Recipient caches store information regarding previous recipients of communications. The information on recipients includes when the recipient was last contacted and the frequency with which a recipient is contacted. In embodiments, a mobile device requests a recipient cache from a server. When a user types a string of text, the mobile device then uses the recipient cache as well as the contacts and emails on the mobile device and resolves a recipient list. In other embodiments, a recipient cache on a server is updated when a mobile device sends a message with new recipient information. In another embodiment, a server resolves conflicting messages by using recipient information.