I finally received a response back from the webmaster
at senate.gov. I've cut and pasted it below. The thing is --
none of the organizations we host *add* addresses without
the request of the recipient. It's against our policy.
I suspect it's not the senators themselves that add themselves,
but someone on staff who looks out for their mail. (For many
of these lists, we collect profile data about subscribers
and quite often I've noticed that it is actually an assistant
or a staffer subscribing the senator.)
So, here we host a lot of lobbyist groups and non-profits
and what their webmaster is saying is we should tell these
groups that they can't let U.S. senators subscribe.
This still doesn't settle the issue why their mail server
continues to kick back autoresponder messages for some
senators 4 days after a mailing was delivered every 2 hours. :(
>We checked our system and it is not clear why you are having this problem.
>Senators' public e-mail systems almost always respond to messages with an
>autoresponse, therefore, it is not wise for an organization to sign up a US
>Senator's public email address for an opt-in distribution list such as
>You probably would not encounter this problem with distributions to Senators'
>staff members, as personal staff accounts rarely, if ever, use
>I suggest removing Senators' public email addresses from your distribution
>lists. I believe this would go a long way toward minimizing some of the
>problems you're having, and such addresses are not, in any case, intended for
>this type of use.