Postage for Large Envelopes & Flats

Looking to mail a large envelope? Here, you'll find up-to-date rates for mailing flats via the USPS as well as information on letter dimensions, requirements, and more.

This pack includes 200 9x12 Flat size Certified Mail Envelopes. Each envelope holds up to 63 pages of paper, is bright white in color and includes the

Certified Mail Envelopes Flat Size 9x12 - Pack of 200 Envelopes for Certified Mail Labels

How to Mail Large Envelopes & Flats

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Postage for Large Envelopes & Flats

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Postage for Large Envelopes & Flats

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