Boooo: It looks like GMail is currently listing the daily e-mailed Sheldon strips as “spam” mail, and placing the strip in your Junk folder. So for the 1-2,000 of you who get Sheldon via e-mail, and are GMail users, go into your Junk folder and mark them as “Remove Label Junk”.
And if you happen to work at Google…man, throw me a bone with these dang spam algorithms. It happens every 6 months or so. 🙁