Mach5 Mailer - Version 1.37 Your contacts want personal attention. Mailer is a fast and easy way to send personalized e-mail to thousands of customers. Mailer works just like Microsoft Word; just choose a database, type your message, and click Send. But Mailer includes powerful features like conditional (IF) field insertion, flexible rules based boolean recipient selection, "preview" e-mail merges, and automatic UUEncoded file attachments. And Mailer can send tens of thousands of messages per hour, speeding through even the largest mailing.