Thank you so much! I will try it on my next order.
Thank you for the quick reply. I tried creating a custom package but I still get the error message because my envelope is 12-1/2″ x 9-1/2″.
Gerhard,
I am getting the same error; however, large envelopes (or flats) may be sent first class if max size is 15x12x3/4 and max weight is 13 oz or less. See https://www.usps.com/ship/first-class-mail.htm for verification. Will the fix include large envelopes?
Thank you
