Introduction
This error occurs when your account has been blocked due to spam complaints received through Feedback Loops (FBL) or bounce blocks. The error response will clearly indicate which type of block you’re experiencing:- 550 Suppressed [FBL]: Blocked due to spam complaints via Feedback Loop
- 550 Suppressed [BOUNCE]: Blocked due to bounce blocks from the receiving provider
What is a Suppressed Block?
A Suppressed block is a security measure implemented when we receive spam complaints about specific email addresses (FBL block) or when emails are consistently bounced by the receiving provider (BOUNCE block). The response code will show either[FBL] or [BOUNCE] to indicate the specific reason for the block. Here’s what you need to know:
- Feedback Loop Blocks (550 Suppressed [FBL]): Email providers send us automated notifications when recipients mark messages as spam
- Bounce Blocks (550 Suppressed [BOUNCE]): Emails are bounced by the receiving provider for reasons including:
- SMTP authentication required
- Mailbox does not exist
- Mailbox full
- Other delivery failures
- Scope: The block typically affects the specific email address in question, although it can be domain-wide in some cases
How to Address This Error
You can remove suppression blocks through the dashboard by navigating to Outbound -> Suppression. However, please be aware:- Removal Limits: There are limits on how many times you can remove a suppression block
- Reputation Impact: Removing a suppression block may impact your sending reputation
- Best Practices: Before removing a block, ensure you’ve addressed the underlying issue:
- For FBL blocks: Review your email list collection methods and sending practices
- For BOUNCE blocks: Verify email addresses are valid and check your SMTP authentication setup