So, Uh, Are We Doing This Right?
Testing both pre-postal mail and post-postal mail outbound e-mails saying, “Watch for our letter in your mail!” or “Did you receive and respond to our recent letter?”
You will, of course, split the outbound mail file into those who will and those who will not be receiving e-mails. But you need to be sure you are splitting the file of those who have e-mail addresses, not just those on your mail file. There is a strong argument that the mere presence of an e-mail address on your file is an indicator of a more dedicated donor.