1. A computer implemented method for assisting email users, comprising: providing an address store associated with a user; gathering email addresses from at least one archive and constantly scanning new inbound emails addressed to the user on receipt and new outbound emails from the user for email address information; determining a relevance to the user of one or more email addresses in an email message addressed to the user based on a heuristic, the heuristic weighting the relevance relative to a repeated appearance of the one or more email addresses, wherein determining the relevance based on the heuristic further comprises: determining if the email message addressed to the user includes more than one email address; computing a ratio of known email addresses to unknown email addresses in the email message based on the determining; assigning a relevance weight to the unknown email addresses in the email message based on the ratio; and marking the email addresses in the email message that are unknown as relevant if the relevance weight exceeds a pre-determined value; storing relevance information for an email address in the user address store and storing non-relevant email addresses for the user; and altering an email messaging user interface presented to the user based on stored relevant and non-relevant information for an email address.
4. The method of claim 1 wherein the heuristic comprises marking any email address as relevant and applying a subtraction algorithm.