SMTP2GO Bounce Rate: What Good, Fair and Poor Mean and How to Bring It Down
SMTP2GO wants your 30-day bounce rate under 5%; above that it says the problem is usually your mailing list. It counts soft and hard bounces together, grades 5% to 10% as Fair and anything above 10% as Poor. Hard-bounced addresses are only blocked for 7 days and then get tried again, so the fix belongs in your own database: verify the list your app or newsletter sends to, remove invalid addresses at the source, and stop new bad ones getting in at signup.
What SMTP2GO says
From SMTP2GO's support docs, read 8 November 2026:
- Bounce and Spam Percentages: the dashboard bounce rate "is the percentage of emails that you have sent in the last 30 days that have bounced back. This figure includes both soft and hard bounces." "You should aim to have a bounce rate below 5%. Anything higher usually indicates a problem with your mailing list."
| Bounce rate | SMTP2GO rating |
|---|---|
| 0 to 5% | Good |
| 5% to 10% | Fair (a little too high) |
| Above 10% | Poor (a lot too high) |
- Spam rate "should be below 0.10%, and if you send over 50,000 emails per month it should be below 0.05%."
- Bounces and Rejections: SMTP2GO "automatically blocks (for a period of 7 days) any attempt to send to an email address that has hard-bounced ... After 7 days, the hard-bounced email address will be automatically unblocked". "You should, therefore, remove hard-bouncing email addresses from your local mailing list." Soft-bounced addresses aren't blocked, and no bounce is retried.
SMTP2GO's sending limits post also says new paid accounts are capped at 1,000 emails a day during a one-time review.
Why the 7-day block isn't enough
If your app sends weekly digests to every user, a dead address bounces, sits blocked for a week, and bounces again the week after. Each round counts toward your 30-day rate. The fix is to mark the address undeliverable in your own database so your app stops trying, and to check addresses before they're saved.
Step 1: find where the bounces come from
- Signup forms with typos (
gmial.com) or bot signups. - Old user tables that were never mailed until a new feature started sending.
- Imports from a CRM or a previous provider.
Pull hard bounces from the SMTP2GO reports, and check whether they cluster on one domain (bounces from one domain) or one form.
Step 2: clean the list behind it
- Export the addresses your app or newsletter sends to.
- Dedupe with remove duplicate emails and fix typos with the email typo corrector.
- Upload to the verify page for a live SMTP mailbox check.
- Mark invalid addresses as undeliverable in your database. Keep risky ones but watch them; drop disposable addresses if your terms allow.
Step 3: stop bad addresses at signup
Check each address when it's entered, before it's saved. The real-time email verification API and email verification API quickstart show how; for forms, see block disposable emails at signup. Note that the API isn't part of the Unlimited plan: each plan includes a set number of API calls.
What checking costs
- Starter, $9 a month: 2,500 checks.
- Pro, $39 a month: Unlimited email verification.*
- Business, $99 a month: the first 300,000 checks a month at full speed, 5 seats.
- Agency, $249 a month: the first 750,000 checks a month at full speed, 15 seats, client workspaces.
*Pro fair use: the first 100,000 checks a month at full speed, then slower, never cut off. Unlimited covers email verification, not API calls. See pricing. Check your list free: 100 checks with a Google sign-in, no card.
More reading: hard bounce vs soft bounce, Postmark bounce rate, Amazon SES bounce rate review, and the email verification API.
Common questions
What is a good bounce rate on SMTP2GO?
SMTP2GO says to aim below 5%, and grades 0 to 5% as Good, 5% to 10% as Fair and above 10% as Poor. That rate includes soft and hard bounces over the last 30 days.
Why does SMTP2GO keep sending to addresses that hard-bounced?
Its Bounces and Rejections article says it blocks a hard-bounced address for 7 days, then automatically unblocks it. If the address is still bad it bounces again, which is why SMTP2GO tells you to remove hard bounces from your local mailing list.
What are rejected emails in SMTP2GO?
Attempts SMTP2GO blocked because the recipient hard-bounced in the past 7 days, reported spam, unsubscribed or was added as a suppression. Sends from an unverified sender also show as rejected. SMTP2GO says to aim for zero.
Does SMTP2GO retry bounced emails?
No. Its docs say an email that bounced, hard or soft, won't be retried; the bounce is the final result for that email.
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.