When attending a wedding do you put name on outside of envelope?

If the envelope stays BLANK, then anyone can take that envelope. Write the

names of both Bride and Groom on envelope...i.e: "Mr. and Mrs. Smith"

Answer:Yes. You should put the name of the addressee/s in the envelope. If the envelope is intended to be sent through mail, you should also include the complete address. You can google wedding envelopes or wedding etiquette online. A list of wedding envelope etiquette tips are there to help you in addressing your wedding envelopes. For more wedding envelope tips, you can check the link I added below.