Flat Rate Envelope Cost 2024. The 12.5 x 9.5 flat rate envelope: Ship using free flat rate boxes and envelopes (envelopes and small boxes up to 4 lbs, medium and large boxes up to 20 lbs), starting at $30.90.

India post gazette notification on standardization of mails [192 kb] weight (in gms) length (in cm) width (in cm) height (in cm) article value (in inr) periodical value. Book packets containing printed books (maximum weight 5kg) for the first one hundred.