While it varies from place to place, some post offices will allow you to hand cancel envelopes yourself. You'll have to stamp all the envelopes in the post office, but you'll be able to see that everything was handled carefully.

Does the post office hand stamp letters?

Instead of machine processing, you can request that your envelopes be processed by hand. Your postal clerk will mark each postage stamp, on each envelope, with a special rubber stamp noting the current date and the postal location. This bypasses the need for the envelope to be sent through their sorting machines.

How much does it cost to hand stamp a letter?

Most First Class Mail letters include general correspondence such as billing invoices, credit card statements and birthday cards. These items typically weigh one ounce or less. The cost of a one-ounce First Class Mail stamp is $0.58 at the Post Office, or $0.47 if you buy and print stamps online using Stamps.com.