Message ID

A message ID is the unique identifier issued by an email service provider (ESP) used to track a specific message. This ID is composed of a string of random alphanumeric characters, and it’s unique to the message sent to recipients, regardless of how many recipients there are. It also includes the email client’s name to indicate the sender. Here’s an example:

<KIYjfnefhuw6ehtwj4nfj+reuihun00Khis-HIAhdHFBb714@mail.emailclient.com>

Use Message ID with Mailgun to view all events associated with a particular email to stay on top of bounces, irregular activities, or details of successful delivery. Keep an eye on your events via Mailgun’s Events API to gauge your email program’s health.