Why did my email bounce?
A bounce means the recipient's mail server didn't accept your message. That sounds alarming, but bounces are a normal part of email — what matters is which kind you got, because the two kinds mean very different things and Bird handles each one for you automatically.
Hard bounces: the address doesn't work
A hard bounce is a permanent failure. The receiving server said, definitively, that it will never accept mail for this address — usually because the address doesn't exist (a typo at signup, an employee who left, a mailbox that was deleted) or because the domain itself can't receive mail.
Because retrying a hard bounce is pointless, Bird doesn't. Instead, the address is automatically added to your suppression list, and any future send to it is rejected before it ever leaves Bird. This protects you: repeatedly mailing dead addresses is one of the strongest signals mailbox providers use to mark a sender as untrustworthy, so stopping those sends keeps your reputation intact.
One thing Bird can't do for you: remove the address from your own list. If your mailing list, CRM, or database still contains hard-bounced addresses, clean them out — keeping them around inflates your contact counts and, if you ever sync your list to another tool, risks mailing them again from somewhere else. The list hygiene guide covers how to keep your list clean over time.
Soft bounces: a temporary problem
A soft bounce (also called a deferral) is a temporary failure. The receiving server couldn't take the message right now — the mailbox is full, the server is busy or briefly unavailable, or the provider is slowing down incoming mail — but it may well accept it later.
Bird retries soft bounces automatically. Most resolve on their own: the message is delivered on a later attempt and you never need to do anything. Only if the retries keep failing over an extended period does Bird give up and record the recipient as bounced. Soft bounces do not add the address to your suppression list, because the address itself is fine.
If you're seeing a delay rather than a failure, that's usually this retry cycle in action — see Delivery delays & retries.
Where to see why a specific recipient bounced
Every message in Bird tracks its recipients individually, so one send to many people can have some delivered and some bounced — and you can see exactly which is which.
Open the message's detail view in the dashboard. It lists each recipient with their outcome, and for bounced recipients it shows the reason the receiving server gave — the actual response from the other side, like "user unknown" or "mailbox full". That reason tells you whether you're looking at a dead address (hard) or a passing problem (soft), and it's the same information Bird used to decide whether to suppress or retry.
What to do about bounces
- Hard bounces: nothing to fix on Bird's side — the address is already suppressed. Remove it from your own list so it doesn't come back.
- Soft bounces: usually nothing at all — Bird is retrying. If the same addresses soft-bounce on every campaign, the mailboxes may be abandoned and worth removing anyway.
- Lots of hard bounces at once: that's a list-quality problem, not a one-off. A high bounce rate can slow or pause your sending — see Why was I throttled or paused? — so pause the campaign and clean the list first.
Related pages
- Delivery delays & retries — what happens during the retry cycle and what "delivered" really means
- Why was I throttled or paused? — what sustained high bounce rates trigger
- List hygiene — keeping bounce rates low in the first place
- Suppressions — the developer guide to how the suppression list works and how to manage it