Expn has now been disabled on the MIT mailers in order to provide better privacy for mailing lists. The disabling of expn will reduce the ability for end users to debug mailing list problems, but the Athena User Accounts Office should still be able to aid such users in debugging those problems.
Authorized staff members should still be able to obtain the same information expn provided, via a new web based utility. Click Here to proceed to the web based expn. (MIT certificate required).