This is a great question @talonso23
! While it is not required, it is considered good manners to let your list members know when you receive their exchange, either by sending them a PM via the forum or posting to the exchange thread.
In terms of whether we know you really sent the exchange, it is best practice to take a photograph of your exchanges completed with postage prior to sending. This is
for several reasons:
1. It is a record of what you did for your own personal portfolio.
2. If an envelope goes missing or your whole batch (goodness no!), you can trouble shoot to see if something was wrong with the address.
3. It's proof you actually mailed your exchanges.
I do ask from time to time for people to let me know if they do not receive their exchanges. I can then see if there are repeat misses or if perhaps one or more was just lost in the mail (it happens). This way I can decide if they can participate in the next exchange.
Sadly, this summer we had people sign up and then halfway through say, "never mind I'm too busy." But they would still be receiving. Not fair. While too late to do anything about it, those people are not able to participate in future exchanges.
On the flip side, things do come up, emergencies, jobs, children, etc. As long as those folks let their groups know and eventually send their exchange (even if late), they can still participate at a future date once their exchanges are complete.