9. A method comprising: generating, by an email server, a topic map of email messages stored on the email server, the topic map indicative of a frequency of a topic being in email messages received or sent by a user with an account on the email server; generating, by the email server, an author map of users with accounts on the email server, the author map comprising connections between pairs of the users with accounts, each connection being assigned a weight based on a frequency of communication between the users associated with the connection; receiving, by the email server, an email message from an author, the email message directed to a receiver; determining, by the email server, a relevance score of the email message with a third user based on the frequency of a topic of the email message associated with respect to the third user and the weight of the author map connection between the author and the third user; and sending, by the email server, an alert message associated with the email message to an email client of the third user in response to the relevance score being greater than a predetermined threshold.
9. A method comprising: generating, by an email server, a topic map of email messages stored on the email server, the topic map indicative of a frequency of a topic being in email messages received or sent by a user with an account on the email server; generating, by the email server, an author map of users with accounts on the email server, the author map comprising connections between pairs of the users with accounts, each connection being assigned a weight based on a frequency of communication between the users associated with the connection; receiving, by the email server, an email message from an author, the email message directed to a receiver; determining, by the email server, a relevance score of the email message with a third user based on the frequency of a topic of the email message associated with respect to the third user and the weight of the author map connection between the author and the third user; and sending, by the email server, an alert message associated with the email message to an email client of the third user in response to the relevance score being greater than a predetermined threshold. 10. The method of claim 9 , wherein the topic associated with the email message is based on analysis of text of the email message.