Salutations and Other Wording
As for the wedding invitation envelope wording, you should address the inner envelope with only the names of the guests, whereas the outer envelopes should contain the complete names and mailing addresses of your guests.
In addition, outer envelopes should only be addressed to the adults you are inviting or the specific person. Include others, such as guests and children, on the inner envelope. For example, if you want to invite the Douglas family, address the outer envelope to Mr. and Mrs. Kent Douglas. Address the inner envelope to Mr. and Mrs. Kent Douglas on the first line and Stephanie, Thomas and Corrine on the second line. List the children in order of their ages, beginning with the oldest child. If children are not invited to the wedding, do not include their names. In addition, if you are inviting adult children who live in their parents' homes, send them individual invites.
Be sure to use professional titles for your guests when appropriate, and always spell them out, such as Doctor, Reverend or Lieutenant. If the husband uses the title, address the invite to Reverend and Mrs. Alfred Jones, for instance. If the title belongs to the wife, write her name first, such as Doctor Rose Williams and Mr. Jonathon Williams.
If a couple is unmarried but lives together, simply list both of their names in alphabetical order. If you want to invite a couple who does not live together, address and send the invitation to the person to whom you are closest. Address the inner envelope to both of them, with the person to whom you mailed the invitation listed first.
Spell out all of the words in your guest's mailing address, such as the street and state names. For instance, while you might write 18 E. Columbia Ave., Jamestown, N.Y. 14701 to address a standard letter, the correct wedding invitation envelope wording would be 18 East Columbia Avenue, Jamestown, New York 14701.
One final thought: Address both your inner and outer envelopes prior to stuffing the invitations in order to avoid unsightly bumps in your lettering or tears in the paper caused by the bulk of the invitations. Doing so will save you time and frustration, helping you to get those invitations in the mail.
For more helpful hints and advice, check out Tips and Resources for Making Your Own Wedding Invitations.