Mastering Email Deliverability: Navigating and Resolving SendGrid Blocks

Understanding Email Blocks in SendGrid

Email blocks occur when a message is rejected due to issues related to the message itself rather than the recipient's address. Several factors can lead to an email being blocked:

1. Your mail server IP address has been added to a deny list or blocklist.
2. The ISP has blocked your mail server IP address.
3. The content of your message triggered a filter on the receiving server.


Identifying the Reason for a Block

Within SendGrid, each block comes with a "Reason on the Block." This detail helps clarify why the email was not delivered. In many cases, it's feasible to have your IP address delisted from a blocklist. Some lists even automatically remove IPs after a certain period, offering some relief and action points for senders.


Adjusting message content can also resolve issues related to content-based blocks, ensuring smoother email delivery in future attempts.


Handling Blocked Addresses

What sets blocked addresses apart within SendGrid is that new messages directed at these addresses will still be attempted. Since every message can differ in content, subsequent emails may bypass earlier blocking triggers.


You have several options to manage blocked addresses within SendGrid:

  • Filtering: Utilize the calendar icon at the top right corner of the blocks page to search for blocks within specific date ranges.
  • Removing Recipients: After selecting recipients using checkboxes, you can opt to remove them from the list of blocked addresses.
  • Downloading Information: For record-keeping or analysis, you can download details of blocked addresses as a CSV file by clicking the gear icon and selecting "Download CSV."

Additional Context on Blocked Emails

Blocked emails are indicative of email delivery challenges — they manifest due to deny lists or ISP measures against your IP address, or because certain messages tripped receiving server filters.

These instances get cataloged under "Blocks" within Email Reports. Blocks are transient compared to bounces; this list accumulates messages either directly refused by an ISP or deferred beyond 72 hours.

It's crucial to note that being on SendGrid’s block list doesn't equate to automatic email suppression, akin to what happens with bounce and unsubscribe lists. Subsequent sends targeting these emails are processed normally.


Navigating SendGrid

To locate and manage blocks:
1. Go through `Suppressions > Blocks` in your SendGrid dashboard.
2. Review and act upon items based on their block reason, aiding in fine-tuning your approach for higher deliverability rates.

Remember: Unlike our other suppression lists where new sends are restricted, emails directed at previously blocked addresses will proceed unless dictated otherwise by new criteria or similar blocking conditions reemerge.

SendGrid strives for transparency and control in managing email deliverability issues such as blocks, supplying you with tools and information required for comprehensive management. Should you encounter difficulties understanding specific block incidents or need further clarification, our Support Team is always ready to assist you towards optimal solution pathways.

Happy mailing!

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