Understanding Bounce Handling
What a bounce really is, how Vecta tells a dead address apart from your own broken settings, and why that matters enormously.
A bounce is a permanent rejection by the receiving mail server: most often because the mailbox doesn't exist. Repeatedly mailing dead addresses is one of the strongest signals that you're a spammer, so bounces must be removed from your list quickly.
Three kinds of failure
| Kind | Typical response | Vecta's action |
|---|---|---|
| Temporary | 451 busy, connection dropped, 421 throttled | Retry later, up to 5 attempts with growing gaps |
| Bounce | 550 5.1.1 user unknown, mailbox unavailable | Mark contact bounced + suppress permanently |
| Your-side | 535 auth failed, 554 relay denied, 552 too large | Record the send as failed; contact untouched |
Why the third row is the important one
If your SMTP password expires, every message fails with a 5xx error. A naive "5xx means bounce" rule would mark your entire contact list as dead and suppress all of it permanently. Vecta only suppresses when the receiving server rejected that specific address.
What happens on a bounce
- 1The send record is marked bounced, keeping the server's exact message.
- 2The contact is marked bounced. This is on the person, not the list.
- 3The address is added to the suppression list with reason
bounced.
From then on they're skipped everywhere. You'll see them on your lists with a Bounced badge, so you know why the list count and the send count differ.
Keeping bounce rates low
- Under 2% is healthy. Above 5% puts your reputation at real risk.
- A spike usually means an old segment or an imported list that was never validated.
- Never re-import a file that previously produced many bounces.
Bounces detected at send time
Vecta sees rejections that happen while handing the message to your server. A message accepted then bounced hours later arrives in your own inbox as a bounce notification. Check it and suppress manually if needed.
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