What’s the impact of “blocked” vs “bounced”?
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Both blocks and bounces stop your email from reaching the recipient, but they're diagnosed and fixed in completely different ways. Confusing the two is a common mistake that sends senders chasing the wrong problem.
A bounce happens because of the destination. The address doesn't exist, the domain has expired, or the mailbox is full. It's a problem with the address you're trying to reach, not with you as a sender. Clean your list, and bounces go down.
A block happens because of you. The receiving server rejected your message based on your domain's reputation, your IP address, your authentication setup, or your content. Common block reasons: your domain is on a blocklist, your SPF or DKIM isn't passing, or your content triggered a content filter. Blocks usually return 5xx SMTP codes with messages like "mail rejected" or "sender reputation too low."
The diagnostic difference: if you're getting bounces across a wide range of addresses, it's a list quality problem. If you're getting blocks from specific mailbox providers (like everything going to Gmail is failing but Outlook is fine), it's a reputation or authentication problem at that provider. Blocks are the more serious signal because they mean the receiving server actively distrusts you. Bounces are usually fixable with list hygiene. Blocks often require diagnosing authentication, reviewing your Google Postmaster Tools data, and sometimes reaching out to the blocklist for delisting.
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