Unsolicited promotional emails, commonly termed ‘spam’, are more than familiar to the average email user. However, to date, spam mail has largely been ignored by the linguistic community. The present paper addresses this research gap by presenting a genre analysis of 121 medical spam mails. The analysis concentrates on the macro-textual level, and reveals that unsolicited promotional emails undoubtedly belong to the promotional genre. However, a contrast of previous research on offline promotional letters shows differences between the conventional patterns underlying such letters and those underlying spam emails. These differences are explained with reference to the particular contexts of use, spammers being, namely, forced to deal with a high level of competition from other spam mails, a bad reputation, an extremely fast pace of communication, the risk of being filtered out by spam mail filters and also legal restrictions.