what should be included in the formal invitation that is mailed out. most standard formal invites include both wedding and reception invitations as well as a response card and map to the wedding location if needed.
even though the invitations that you order may arrive months before your wedding, they are not supposed to be mailed out until 4-6 weeks in advance. if you want to send an announcement before that date, then a save the date card would be acceptable. sending the invitations too early could result in some guests forgetting the event by the time it arrived and sending them too late could not give some guests enough time 