SieveHow to Reduce Your Email Bounce Rate
A bounce is a message that could not be delivered. Hard bounces mean the address does not exist, soft bounces mean a temporary problem like a full mailbox. Mailbox providers watch your bounce rate closely, because senders who keep mailing dead addresses are usually senders with bought or ancient lists. A good working target is to keep your bounce rate under 3 percent, and staying there is less about reacting to bad campaigns and more about controlling what enters and stays on your list. Here is how to get it down and keep it down.
Step 1: Stop bad addresses at the front door
Most bounces are born at signup. Someone mistypes their address, enters a throwaway from a temporary email service, or fills your form with garbage. Every one of those becomes a future bounce if it gets onto your list unchecked.
The fix is to validate at the point of capture. At minimum, check that the address is well formed and that its domain actually has mail servers (MX records), which instantly catches typos like gamil.com. Better still, verify the mailbox itself exists before the address enters your list. If you cannot verify in real time, a confirmation email (double opt-in) achieves something similar: an address that never confirms never gets mailed. Whichever route you choose, the principle is the same, prevention at signup is far cheaper than cleanup later.
Step 2: Clean the list you already have
Lists decay naturally. People change jobs, abandon inboxes, and companies shut down, so an address that was fine two years ago may be gone today. Before your next big campaign, run the full list through validation and sort the results into three buckets: clean addresses that are safe to send to, risky ones like role inboxes (info@, sales@) and catch-all domains that deserve caution, and rejected ones that are invalid, disposable, or simply do not exist anymore.
Remove the rejected addresses entirely. For risky ones, consider a separate, smaller send or a re-permission email rather than including them in your main blast. This single cleanup pass typically removes the bulk of the addresses that would have bounced. Sieve's free plan covers unlimited DNS-layer checks plus 100 live mailbox verifications a month if you want to try this on a sample of your list first.
Step 3: Act on every bounce, immediately
When a campaign produces hard bounces, suppress those addresses at once and never mail them again. Most sending platforms can do this automatically, so confirm the setting is on rather than assuming it is. Mailing an address that already hard bounced is one of the clearest signals of carelessness you can send to a mailbox provider.
Soft bounces deserve patience but not infinite patience. A full mailbox may empty next week, but an address that soft bounces across several consecutive campaigns is usually abandoned. A sensible rule is to retire an address after three to five consecutive soft bounces.
Step 4: Prune the silent and keep a rhythm
Addresses that never open or click for many months are the next bounces waiting to happen, and mailing large volumes of unengaged contacts drags your reputation down even before they bounce. Run a re-engagement campaign for long-silent subscribers, something honest like asking whether they still want to hear from you, and remove those who do not respond.
Finally, make hygiene a rhythm instead of an emergency. Validate new signups as they arrive, revalidate the full list a few times a year and before any major send, and watch your bounce metrics after each campaign. A list managed this way stays under that 3 percent line without heroics, and your open rates tend to rise as a side effect, because a larger share of your sends reach real people.
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Frequently asked questions
What is a good email bounce rate?
Keep your bounce rate under 3 percent, and the lower the better. Sustained rates above that tell mailbox providers your list contains many dead addresses, which damages your sender reputation and pushes even your legitimate mail toward the spam folder. Rates near zero are achievable with validation at signup and regular list cleaning.
What is the difference between a hard bounce and a soft bounce?
A hard bounce is permanent: the address does not exist or the domain cannot accept mail, so the address should be removed from your list immediately. A soft bounce is temporary, such as a full mailbox or a server hiccup, and can be retried. An address that soft bounces across several consecutive campaigns is usually abandoned and should be retired too.
Does a high bounce rate really affect deliverability?
Yes. Mailbox providers like Gmail and Outlook track how much of your mail bounces, and a high rate marks you as a sender with poor list hygiene. The penalty is not limited to the bad addresses: providers respond by filtering more of your mail overall, including messages to your engaged, real subscribers.