~~~ and upon delivery I noticed the flaps were w/o adhesive... at which time I got into a habbit of running a strip of tape over the flap with another strip run horiz over the address so if anyone tried to lift the flap tape they would have to tangle with the second layer of tape, first, which also protects the address should it get wet, soiled or partially torn in that area.

I also noticed about 20 years ago when trading documents with European collectors that they would run a full strip of Scotch tape horiz and vert over the entire envelope to help prevent it from being torn completely open allowing the documents to slide out freely...

Happy Birthday...