May be you send them a mail. ThunderBird I use add automaticly to AddressBook every person I reply to.
May be they are manualy add you to their AddressBook. If somebody somehow is breaked UT all members will receive this kind of letters, I suppose.
Against Stupidity the Gods themselves Contend in Vain - Johann Christoph Friedrich von Schiller
The only thing normal about database guys is their tables.