When deciding whether an email should be blocked or pre-blocked, Mailjet's system analyzes multiple parameters, including your sending history. The aim is to predict deliverability issues and prevent emails that have little to no chance of reaching the recipient's inbox from being sent. This helps protect your sender reputation from negative impacts.
Here are the most common reasons why emails may be blocked:
- Spam Report: A recipient reported your email as spam.
- Hard Bounce History: The email address has previously resulted in a hard bounce.
- Templating Errors: Errors in the templating language can also cause emails to be blocked. If there is a syntax error in your message when using Mailjet's Email Editor, the email will not be sent and will appear as "blocked" in your statistics. However, this block is not permanent—if the next email sent to the recipient has no templating errors, it will be successfully delivered.
For help troubleshooting templating errors, visit our article: Troubleshooting Your Test Emails.
To determine why a specific email was blocked, go to the Stats page and click on the subject line of the blocked email. The "details" column will provide the reason for the block.
You may also come across the label "spam pre-blocked" in your statistics. Before campaigns are sent, our system performs an anti-spam scan to detect any potential spam triggers. If your email is marked as "spam pre-blocked," it means that it would likely have been classified as spam by the recipient's server.
For more details, refer to: Words That Will Trip The Spam Alarm.
If you're certain that an address is valid and the recipient wants to continue receiving your emails after a spam report or hard bounce, you can open a support ticket with our team for assistance.