After exchanging addresses you can mail your seeds.
The seed packs are carefully wrapped with bubble wrap and placed in an envelope or you can use a padded mailer to send them. You need to cushion them in fat packaging so they don't go through the Post Office automatic mail sorting machines.
Always make sure that your email address is included with the seeds. If the trader needs to contact you later on the email address is right there for them to use.
Always write your return mailing address on the outside of the envelope.
The post office will charge a bit more for mailing a fat letter, it is because the letter gets out-sorted into "hand-mail". It's too fat to go through their high-speed mail sorters. The width should always be over a 1/4" thick to keep a letter out of the mail-sorters because these high speed machines can crush the seeds to powder.
It's courteous to let your trader know when their seeds will be on the way. If you've promised to mail on Monday, but something happened to delay that then email the trader to let them know when the seeds will be mailed...and keep that date!
A good trader is a responsible trader. Good traders use bubble wrap or padded mailers to assure that the seeds are not crushed during their trip through the mail.
Bubble Wrap lined envelopes and Padded Mailers will require extra postage to mail. This NonMachinable Surcharge assures that your packages will be sorted by hand. The seeds you send will not go through automated sorters that can crush the seeds inside your padded envelope or mailer.
Wikipedia.Org
Sealed Air Corporation
United States Post Office
