Sending cold emails through MailBluster is against the terms of use of MailBluster. You cannot send unsolicited emails to a receiver without prior contact. That is, you are not allowed to send emails to those who are not your subscribers. This is according to the guidelines of your SMTP provider (AWS, Postmark, Mailgun, SMTP2GO). You must have prior contact first, and your leads have to be your subscribers. If you send cold emails, then your SMTP provider account will be paused/suspanded. It might also result in blocking your MailBluster and SMTP provider account forever.
Sending cold emails using MailBluster
Last update: September 15, 2025