You should mail your invitations six to eight weeks before your wedding. If your wedding is taking place during a busy time of the year (such as Christmas or a three-day weekend), you should mail your invitations ten to twelve weeks before the big day. This will give your guests ample time to plan their holidays and weekends around your wedding day.
Also, if you are having a destination wedding, you should definitely mail your wedding invitations early. A good time would be about ten to twelve weeks before the wedding. You want your guests to be able to make their travel plans in order to attend your wedding. Not only will they have to make travel plans, but they will also have to make sure that they have vacation time off from work.