MailJet is a newsletter software used to send customized emails to a list of recipients. MailJet is a direct marketing software, which can be used to send out press-releases, newsletters and announcements to your customers, subscribers and partners. MailJet comes with a built-in contact list manager and allows sending personalized emails by using tags. All you have to do to start your first bulk email marketing campaign, is to copy you email-account settings from your email software and start sending out messages in seconds.