We keep a list of blocked senders and recipients on our servers. They are up for discussion and we are happy to talk if you feel that this has negatively impacted you.

First, let’s talk about why these blocks are activated.

Your sender address has been blocked by Mailix.

The most common reasons are:

• We have seen a significant number of rejected emails from your domain to third-party services.
• You have been caught forging a sender address as your sender address when sending emails, but you do not own the domain in this sender address.
• You have been caught sending from an obviously invalid sender address, clogging up email queues.
• Your sending behavior violates our policies, and not just a little.

Your recipient address has been blocked by Mailix.

The most common reasons are:

• You kept sending emails to someone who didn’t want them, and we wanted you to get a direct error next time.
• You sent absolute junk to a third-party service. For example, 1000 cronjob notifications forwarded to Gmail every day.
• You kept sending many messages to an invalid recipient that doesn’t even exist, and we’re reducing the effort required to constantly spam you with bounce errors by blocking you.
• You have a inbox with full quota and don’t fix this situation for a long time. We would then have to bounce every message sent to that mailbox with “mailbox full” errors, and we don’t want to do that for a long time.

If you want to dispute an entry in our blocklists, please just open a ticket in our customer management interface.