coupons

We have given out an Easter coupons to existing customers that have signed up for the newsletter.  So far we have a good response from that newsletter, but have noticed that only a few have actually applied the coupon to their order.  We are now going through orders applying the discount from the newsletter manually to those who have not applied it.  This is very time consuming for us.  So here is my suggestion:
Have the option to "auto apply a coupon to existing customers that have signed up for the newsletter".  This makes it so much easier for us and for the customer.  I've seen this at other sites and would love to see it here as well.

It's now a couple days later.  We did send out a mail-up message with coupon.  80% of those recipients that did shop, did not use the coupon.  They all thought it would be automatically applied, if clicking on the message.  A big downfall for us, since we had to check each order, manually adjust it, and refund the money.  Is there a way to apply a clickable coupon to it?  I've seen it with other companies sending out coupons.  They give the code so you can share the info, but automatically apply it when clicking on the message.