[Q] Can you re-enter the US from Canada or Mexico on automatic revalidation even with expired E visa?

Yes, but you need a valid I-94 Form, and there are exceptions and limitations.

What is Automatic Revalidation?

The Department of Homeland Security (DHS) U.S. Customs and Border Protection (CBP) has the authority and the responsibility over the admission of travelers to the U.S. Under the automatic revalidation provision of immigration law, certain temporary visitors holding expired nonimmigrant visas who seek to return to the U.S. may be admitted at a U.S. port of entry by CBP, if they meet certain requirements, including, but not limited to the following:

Nonimmigrants who departed the U.S. for brief travel to Canada, Mexico, or an adjacent island (for F and J nonimmigrants) for thirty days or less;
Nonimmigrants with a valid (unexpired) Form I-94, Arrival-Departure Record, endorsed by DHS.

For more info, check out:

http://travel.state.gov/visa/temp/info/info_1299.html

http://cbp.gov/linkhandler/cgov/travel/id_visa/revalidation.ctt/revalida...