A good email bounce rate is one that stays far below the limits your sending platform enforces. Those limits are published: Amazon SES reviews accounts at a 5% bounce rate and may pause sending at 10%, and HubSpot can suspend marketing email when the monthly hard bounce rate passes 5%. A healthy, opted-in list should run well under those ceilings, and any sudden jump is worth investigating even if you’re still “under the limit.”

The catch is that “bounce rate” means different things in different tools, and the number you compare against a limit has to be calculated the same way the platform calculates it. This guide covers the published thresholds, how to compute your own rate, and how to tell a healthy number from a warning sign.

Published bounce rate limits

There’s no single industry standard for a “good” bounce rate, but several platforms publish the points where they take action. These are the most reliable reference numbers available, because they are the rules your account is actually measured against.

Platform	What’s measured	Published threshold	Source
Amazon SES	Hard bounces, over a “representative volume”	Recommended below 5%; review at 5% or more; sending may be paused at 10% or more	AWS docs
Amazon SES (guidance)	Hard bounce rate	“Try to keep your hard bounce rate below 5%,” described as a reasonable goal but not a universal rule across ISPs	AWS docs
HubSpot	Hard bounce rate in a given month	Marketing email can be suspended above 5%	HubSpot KB
Postmark	Bounce rate of all emails sent	Below 10% listed as a condition for sending without a daily limit	Postmark support

Two things stand out. First, the common enforcement line is 5% of hard bounces. Second, these are the levels where a provider steps in, not the levels you should aim for. By the time a platform reviews your account, mailbox providers have usually been seeing your bounces for a while.

What about Gmail, Yahoo, and Microsoft?

Mailbox providers don’t publish a bounce rate threshold. Google’s email sender guidelines, which have applied to everyone sending to Gmail accounts since February 1, 2024, set firm limits for spam complaint rates (keep it below 0.1% and never reach 0.3%) but say nothing numeric about bounces. They do advise automatically unsubscribing recipients who have multiple bounced messages and reducing volume when messages start bouncing or getting deferred.

Yahoo’s SMTP error code page describes an “excessive unknown recipients” error for servers that send to many invalid addresses, and tells senders to remove addresses that bounce. So the large mailbox providers clearly watch invalid-recipient volume. They just don’t tell you the number.

How to calculate your bounce rate correctly

The basic formula is simple:

bounce rate (%) = bounces / emails sent × 100

The details are where people go wrong.

Separate hard and soft bounces

Amazon SES counts only hard bounces in its bounce rate and ignores soft bounces, per its reputation metrics page. HubSpot’s limit is also on hard bounces. If your dashboard shows a combined number, split it before comparing against those limits. Soft bounces deserve their own tracking, but a spike of mailbox-full errors at one provider isn’t the same signal as a list full of dead addresses.

Use sent, not delivered, as the denominator

Bounce rate should be calculated on attempted sends. Dividing by delivered messages inflates the rate and makes comparisons meaningless.

Exclude addresses you never actually tried

Messages your platform skipped because the address was already suppressed shouldn’t count as new bounces. Amazon SES, for example, doesn’t count sends to addresses on your account-level suppression list toward its bounce rate metric (AWS).

Look at the right window

A per-campaign rate tells you about one list or segment. A rolling rate (for example, the last 30 days) is closer to how platforms judge you. Amazon SES calculates its rates over a “representative volume” that varies by account. HubSpot uses a monthly window. Track both views.

A worked example

You send a newsletter to 48,000 contacts. The report shows:

312 hard bounces
590 soft bounces
47,098 delivered

Your hard bounce rate is 312 / 48,000 = 0.65%. Your total bounce rate is 902 / 48,000 = 1.88%. If you’d divided by delivered messages, you’d get 1.92%, a small difference here but a large one on a bad list.

What a “good” bounce rate looks like in practice

Since the only published numbers are enforcement limits, here’s how we suggest reading your own rate. Treat this as a rule of thumb, not an industry statistic:

Your hard bounce rate	What it usually means	What to do
Near zero, stable	Opted-in list, regularly mailed, validated at signup	Keep doing what you’re doing
A fraction of a percent, stable	Normal decay on an active list	Suppress bounces after each send
Rising campaign over campaign	Decay is outpacing your hygiene, or a new source is adding bad data	Find the source; verify older segments
Approaching the 5% enforcement line	An old, imported, or purchased list, or a broken signup form	Stop sending to that segment and clean it before the next send
Above 5%	You’re in review territory on SES and HubSpot	Pause, clean, and fix collection before resuming

The trend matters more than any single number. A list that bounced at 0.3% last month and 1.5% this month has a problem, even though 1.5% is well below every published limit.

Why your bounce rate differs by list type

Different kinds of lists decay at different speeds, so comparing a cold outreach list to a confirmed opt-in newsletter isn’t fair to either.

Confirmed (double opt-in) lists should have the lowest hard bounce rates, because every address worked at least once when its owner clicked the confirmation link.

Single opt-in lists collect typos. The M3AAWG Sender Best Common Practices warn that single opt-in lets unconfirmed addresses, including typos and forgeries, onto a list, which leads to complaints and bounces.

Lists that haven’t been mailed in months collect dead accounts. Major providers close inactive mailboxes on fixed schedules: Yahoo says a mailbox not accessed for 12 months becomes inactive and stops receiving new email (Yahoo Help), Microsoft closes an Outlook.com mailbox if the owner hasn’t signed in at least once in a one-year period (Microsoft Support), and Google may delete personal accounts that haven’t been used within two years (Google). Our post on email list decay covers the other ways lists go stale.

B2B and cold outreach lists decay as people change jobs, and the addresses often come from scraping or enrichment rather than from the person. Expect higher bounces and verify before every campaign. See cold email bounce rate for that scenario.

Signs your bounce rate is a problem (even under 5%)

A spike tied to one source. A new lead form, a partner list, a trade show import. Segment your bounce data by acquisition source and you’ll find it quickly.
Bounces concentrated at one provider. If most bounces come from one mailbox provider and carry x.7.x policy codes, that’s a block, not bad addresses. Check authentication and reputation instead of cleaning your list.
A rising soft bounce rate. More deferrals than usual can mean you’re being throttled because of reputation. Google’s guidelines advise reducing volume until the error rate drops.
Bounce rate climbing with complaints. Old lists produce both. If both numbers rise together, the list itself is the problem.

How to get your bounce rate down

The fastest fixes, in order:

Suppress every hard bounce after every send. If your platform does this automatically, confirm it’s actually on. Our existing guide on suppression list design explains what should go on that list and for how long.
Stop mailing segments you haven’t mailed in a long time until they’ve been verified or re-permissioned.
Validate new addresses at signup, including typo detection and an MX check.
Find and fix the worst source. One bad import can account for most of a month’s bounces.
Authenticate your mail so policy rejections stop looking like bounces.

The full procedure is in How to Reduce Your Email Bounce Rate: A Practical Checklist.

To check a batch of addresses before a send, try the free email verifier. It catches invalid syntax, domains with no MX records, disposable domains, role-based addresses, free-provider domains, and common domain typos. It doesn’t connect to the mailbox over SMTP, so it can’t confirm that a specific inbox exists, but it filters out the errors that make up a lot of avoidable hard bounces.

FAQ

Is a 2% email bounce rate good?

It depends on which bounces you’re counting. A 2% total rate that’s mostly soft bounces on a large send may be fine. A 2% hard bounce rate on an opted-in list is high for that kind of list and suggests decay or a bad source, even though it’s under the 5% line that Amazon SES and HubSpot enforce.

What bounce rate gets you suspended?

On Amazon SES, a bounce rate of 5% or more puts your account under review and 10% or more can pause sending. HubSpot can suspend marketing email when your hard bounce rate exceeds 5% in a month. Other providers have their own rules, so check your ESP’s acceptable use policy.

Does Gmail have a bounce rate limit?

Google doesn’t publish one. Its sender guidelines focus on authentication and spam complaint rates, though they do recommend unsubscribing recipients after multiple bounces and slowing down when you see bounces or deferrals.

Should I include soft bounces in my bounce rate?

Track them, but separately. Most platform limits apply to hard bounces, and soft bounces are often caused by temporary conditions you can’t control. A soft bounce rate that keeps climbing is still worth investigating, because it can signal throttling or abandoned mailboxes.

How often should I check my bounce rate?

After every campaign, and on a rolling 30-day basis. Per-campaign numbers catch a bad segment or import quickly. The rolling number is closer to how your ESP judges your account.

What Is a Good Email Bounce Rate?