How Close Is Your Last Send to an ESP Suspension? Checking Bounce and Complaint Rates Against Each Platform's Own Line
Work out the hard bounce rate (hard bounces ÷ emails sent) and the complaint rate (complaints ÷ emails delivered) for the send you're worried about, then compare them with the line your platform publishes, not a number from a forum. If you're over 2% hard bounces, fix the list before the next send whatever platform you're on.
The ESP bounce limit checker does the arithmetic and shows your numbers against every platform's line at once. Sources: Amazon SES sending review FAQ (read 2 November 2026), HubSpot's suspension article, Brevo's suspension article and the Postmark servers FAQ.
The published lines
| Platform | Hard bounces | Complaints |
|---|---|---|
| Brevo | Above 2% can suspend | Above 0.2% |
| HubSpot | 5% in a month | 0.1% |
| Amazon SES | 5% review, 10% may pause (recommends under 2%) | 0.1% review, 0.5% may pause |
| Postmark | Must stay below 10% | Below 0.1% |
| Instantly | 5% auto-pause by default (adjustable) | Not published |
| lemlist | 10% alert, 50% auto-pause | Not published |
| Mailchimp, Mailgun | Not published | Not published |
The full write-up with every vendor quote is in bounce rate thresholds by platform.
Run the check
- Pick the window your platform uses. HubSpot looks at a month, Brevo at campaigns in the last 24 hours, SES at a "representative volume" it doesn't disclose. For a single campaign, use that campaign's numbers.
- Count hard bounces only. Permanent failures such as "address does not exist" (5.1.x codes). SES says mailbox-full and blocked-IP bounces don't count toward its rate. If your export mixes types, the bounce rate by source tool sorts them.
- Count complaints against delivered mail, not sent.
- Compare with your platform's line and with 2%. The checker also shows how many more bounces the same volume could take before the first enforcement line.
- Read the platform's own reputation page for the number it actually acts on. SES publishes it as
Reputation.BounceRatein the console and CloudWatch.
Why your number won't match the dashboard
SES is explicit: its bounce rate only counts hard bounces to domains you haven't verified, isn't based on a fixed window, and "won't match the counts for any date range that you choose". Sequencers count differently again; Instantly waits for 200 sends before its auto-pause applies. Use your own calculation for headroom, and the platform's figure for where you stand.
If you're over the line
- Stop the next scheduled send to the same list or segment.
- Find the source. One import or vendor file usually accounts for most of the bounces; see finding which list source caused the bounces.
- Verify the rest of that segment, not only the addresses that already bounced, which your platform has suppressed anyway. SES notes that just removing bounced addresses "might not solve the underlying problem".
- If you already have a review notice, read writing an ESP suspension appeal before replying. Platform specifics: Amazon SES bounce rate review, HubSpot suspension appeal, Brevo campaigns suspended.
Limits
The checker uses each vendor's published line, and a platform can act below it. It can't see your platform's internal figure, and it can't tell which remaining addresses will bounce next; that takes a mailbox check.
Where SimpleVerifier fits
Upload the segment at /verify before it's mailed again: valid, risky and invalid download as separate files, so the next send goes to the valid file only. The first 100 checks are free with a Google sign-in. Pro is $39 a month with the first 100,000 checks a month at full speed, then slower, never cut off. See pricing.
Common questions
What bounce rate gets an email account suspended?
It depends on the platform. Brevo names hard bounces above 2% as a suspension trigger, HubSpot suspends at 5% hard bounces in a month, and Amazon SES places an account under review at 5% and may pause sending at 10%. Mailchimp and Mailgun don't publish a number.
Why is my calculated bounce rate different from my ESP's dashboard?
Each platform counts differently. Amazon SES counts only hard bounces to domains you haven't verified, over a representative volume rather than a fixed window, and says you can't calculate its figure from your own statistics. HubSpot measures by month; Brevo looks at campaigns in the last 24 hours.
Do soft bounces count toward the limit?
For Amazon SES, no: temporary failures such as mailbox full, and bounces caused by blocked IPs, don't count toward the bounce rate. Other platforms describe their lines in terms of hard bounces too.
My rate is under the line. Am I safe?
Not necessarily. A platform can act below its published line, and providers such as Gmail react to complaints and engagement as well as bounces. Under the line means you have headroom, not a guarantee.
Check your list before you send
Real mailbox checks over SMTP, and nothing is sent to the address. Sign in with Google and your first 100 email checks are free, no card. Plans for bigger lists are on the pricing page.