I love this resource from our Carlson Craft partner and always share it with brides when they have questions about envelope addressing. We are always happy to answer envelope addressing questions
Inner Envelopes have un-gummed flaps and are often ordered with a colored liner. Address with names only. Do not use the first names of the recipients except when inviting children. Their names should be written on a line below the parents name.
Outer Envelopes- the outer envelope is slightly larger than the inner envelope and the flap is gummed. Address the envelope using formal names and the complete address. Do not abbreviate
Single Outer Envelopes- If you have selected an invitation that does not include an inner envelope, or if you choose not to use your inner envelopes, you may follow traditional addressing rules for outer envelopes. Or create a new way that works best for you.
Mailing Your Invitations- Mail all of your invitations at the same time, 5 to 8 weeks before the wedding date. If you are including response cards with your invitations, include stamps on the return envelope as well. To avoid postage delays, take your invitation ensemble, including all envelopes and enclosures to your local post office to determine proper postage. Be sure to include a return address on each outer envelope.