Here's the deal, though—regardless of whether you email Mr. So-and-So at so-and-so@wustl.edu or at so-and-so@artsci.wustl.edu, it goes to the same friggin' inbox. Why not just use the shorter extension? I know blah@artsci was the convenient shorthand of choice for juniors and seniors, but we in the class of 2006 weren't on the original system for that long before they changed it—so why keep using an outmoded shorthand?
[shakes head] I'm really just mystified to see kids going around noting their email addresses on forms in this shorthand that was developed for use in lieu of writing out three-part email extensions. I'm so very sick of seeing people use that abbreviation. I know, though, it's cool and sophisticated when you can abbreviate everything, and we all want to be cool and sophisticated like the seniors: "Like, omg, welcome to Wash. U. I'll be your tour guide today, I'm an LA '06 in ArtSci, if you have any questions you can email me at dumbass@artsci and I'll be glad to answer them..."