My direct mail has been on auto-pilot since I began outsourcing it several months ago. I sent first class postcards for the first mailer in order to keep the cost as low as possible because I knew that I would have a bunch of “return to senders”. And I used first class postage because I wanted to get the bad addresses back so I could remove or research them before sending out future mailings. All subsequent mailings will take advantage of the standard class mail rates.