Here is at least some proof about envelopes and stamps from Nancy Lapid's About.com Celiac Disease Blog (by the way, if you aren't reading this blog you should be).
Question: Is there gluten in envelope glue or stamps?Nancy also has some other great articles about Gluten myths like...
Answer: No, there is no gluten in envelope glue, according to the international Envelope Manufacturers Association. The Association's website says: "Remoistenable adhesives are derived from corn starch and do not contain wheat or rye gluten."
Furthermore, in the Fall 2007 issue of Gluten Free Living, Amy Ratner reported, "There are actually only a few envelope glue manufacturers in the United States. National Starch & Chemical, a New Jersey company, is one of the largest adhesive suppliers in the world. A company spokesperson says it makes its glue from corn, which is gluten free."
As for stamps, a Post Office spokesman told Ratner there's no gluten in stamp glue either. At any rate, the ingredients in stamp adhesives are much less of an issue, since the vast majority now have pressure adhesive glue and can be pressed onto your mail without the need to lick them.
Can someone get gluten from kissing?
Can You Outgrow Celiac Disease?
Can People With Celiac Disease Donate Blood?
Can There Be Gluten In Breast Milk?
Are maltodextrin and dextrin gluten-free?
Can there be gluten in semen?
Can I eat the turkey if the stuffing has gluten in it?
Are people with celiac disease always thin, or can they be overweight?
Can Gluten Be Absorbed Through The Skin?
Great stuff Nancy!