Gift Certificate sending 25 emails; only one to customer

Every time we send an online gift certificate out through zencart it generates 25 codes, only one gets sent to the customer and the other 24 bounce back into my email as undeliverable. We had to send 3 certificates today and I ended up with over 70 undeliverable messages in my inbox. A while back it only generated 7 codes and briefly it was generating 13.

I'm running Zen Cart 1.3.9h

Could you give a step by step break down of how you are sending a Gift Certificate out?

Under Gift Certificate/Coupons I click on Mail Gift Certificate. For Customer I choose Please Select because the email I send it to is usually someone other than a customer already in our database. <--I always thought that was odd that that was a required field. In the email to section I put the email address then I fill out the subject and amount and message. I click on send message and then I confirm. We double check that it was sent out by going to Gift Certificates Sent and there you can see that it creates a bunch of codes, but only one gets sent to the email.

Does it send numerous NEW emails with GVs ...

Or, is it showing you the OLD GVs previously sent and 1 NEW GV just sent?

It sends me numerous failed delivery emails they say undeliverable address and then it sends 1 successful one to the recipient.

Is this a clean install of v1.3.9h or an upgraded version?

upgrade :) upgraded from 1.3.7

I would recheck the files with something like Beyond Compare and make sure that they are all current and up to date and that nothing was over looked ...