For those struggling with choosing which envelopes to use in your mailings (there are several threads here now that the subject has come up), may I post a suggestion? The FedEx envelope idea has its benefits and problems. So do normal envelopes. Document-sized clasp envelopes, too. There's no "perfect" answer. But the main goal is to get the letter in front of the decision makers. Here's a quick idea to try, and while I haven't tried it specifically for this method, I have done it for similar mailers with great open-rate success. Since many of the methods include attaching their current advertising to the packet, why not cut out a second one and affix it to the outside-back of the envelope you're sending out? If it's a YP.com ad, print it on the back. Or, be creative...cut out their logo from the ad, and use it as the top of the address line. Nothing says OPEN ME like their logo staring them in the face. Just my 2 cents.