Request for mailing list change - obscure email addresses

Can the mail archives/mail list be changed to obscure the email address used to send messages.

eg. instead of a to/from address showing up as

username (at) example.com

can it be changed to

username at xxxxxxxxxx

I have not had any spam to this account, within 24hrs of posting a message to the hobbit list I am now on spam lists.

Maybe the latest version of the mailing list software will do this, an example I can refer to is here:

http://www.sage.org/lists/sage-members-archive/2008/threads.html

Thanks

Craig