Cutting the mustard

The playgroup that Anna and I belong to is very large. It spans the ages of infant to teen and includes more than 250 parents. There's also a very active internet bulletin board system where parents can ask questions, get recommendations for goods and services, post things that are for sale or free, etc. This little gem showed up in my inbox today and I just had to share. I got a good chuckle out of it and would love to know the backstory:

If anyone wants a box with 499 Heinz Mustard Packets ... they're by the
front door. 1139 Rutland. Don't ask. Thanks