Replying to e-mails
Sending an e-mail to the site administrator is great, until he decides to reply. Then we have a problem. When you click Reply, the e-mail that opens is addressed to the site administrator (actually, we set it to info@example.com
if you recall). So, he sends the e-mail to himself, and not to the person who submitted the form.
Yet their e-mail is right there in the e-mail text. Can't we put that in the From Email field? Then the reply will go just where we want it.
Well, yes we could put the e-mail in there (technically using a Dynamic From Email field). But then we find that the administrator no longer receives any e-mails at all!
This is most likely because the site ISP is checking for spammers and one of the checks that they run is to compare the site domain with the domain in the From Email header of the e-mail. If they don't match, the e-mail is marked as "likely spam" and dropped in the bin.
The answer is to use the Reply To Name and Reply To Email headers.