The Easiest Way to Create a Mail Merge in Microsoft Word With the mail merge wizard in Microsoft Word, you can set this up in just minutes. A mail merge lets you compose the base of the message, insert the names, and create all the letters at one time. The nice part about Word's mail merge wizard is that you can use an existing list or create one on the fly. You can also customize various parts of the letter and use the merge for labels or envelopes in addition to emails and letters.