$4.15 extra for a certified mail with a physical return receipt (green card) (not available for APO/FPO/DPO locations).
$0.50 extra for a return envelope.
$1.70 surcharge for USPS First Class and Certified mail flat envelopes (can not be used with a return envelope or a USPS live stamp, and accepts no more than 47 sheets).
$1.85 surcharge for envelopes with more than 6 pages.
$0.23 additional postage and handling for a live stamp on USPS First Class mail only (not available for USPS Express Mail, USPS Priority Mail, USPS Certified Mail or USPS First Class mail with return envelopes or USPS First Class mail with flat envelopes.).