DND, I saw a post where you said that you don't open players envelopes until all envelopes have come in. Thanksgiving is fast approaching and I will guess that your growing tired of looking at seeds everywhere. I thought I would share my ever so simple sorting method when returning seeds for a swap like this.
It's simple!
I buy a 50 pack of dollar store paper lunch bags, each players name is put on one bag. I line them up on the bed in my spare room. As envelopes come in, I drop the seeds into the correct players paper bag until all envelopes have been rec'd. When the last players envelope has been received, all the paper bags are loaded with their return seeds. I start mailing seeds and getting rid of the seedy mess the very day the last envelope arrives.