Is it legal to use USPS padded flat rate envelopes, cut and modified as extra padding, inside a USPS First Class package? - Quora
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Amazon.com : USPS Shipping Template, Mail Measure, Mail Sizer, Slot Template, Letter Envelope Size Guide, Measuring tool for USPS letter flat large envelope : Office Products
![If I'm shipping a package with a Mercari USPS Priority mail label is it ok to use this padded envelope? I've seen lots of things about them only accepting certain types of If I'm shipping a package with a Mercari USPS Priority mail label is it ok to use this padded envelope? I've seen lots of things about them only accepting certain types of](https://i.redd.it/5pl019g41xp71.jpg)
If I'm shipping a package with a Mercari USPS Priority mail label is it ok to use this padded envelope? I've seen lots of things about them only accepting certain types of
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