What is an acceptable email bounce rate?

Hard bounce rates should stay below 2% — most ESPs will suspend accounts that exceed this. The target is below 1%. Soft bounce rates below 5% are generally acceptable. Spam complaint rates must stay below 0.3% at all times; Google specifically flags senders above 0.1%.

What is the difference between hard and soft bounces?

A hard bounce is a permanent delivery failure — the email address doesn't exist, the domain has no MX record, or the receiving server permanently rejected the message. Hard-bounced addresses should be immediately suppressed. A soft bounce is a temporary failure — the mailbox is full, the server is temporarily unavailable, or rate limiting is in effect. Soft-bounce addresses can be retried but should be suppressed after repeated failures.

How does Google measure spam complaint rates?

Google uses its Postmaster Tools to measure complaint rates. The threshold is 0.08% for sustained sending — above this, Gmail may reduce delivery rates. Above 0.3%, Gmail may suspend delivery entirely. The rate is calculated as complaints divided by authenticated messages delivered.

Email Bounce Rate Calculator — Calculate Hard and Soft Bounce Rates

Bounce Rate Calculator

Calculate your bounce rates and spam complaint rate. ISPs track these — high rates damage sender reputation and can trigger sending blocks.

Emails sent

Hard bounces (permanent)

Soft bounces (temporary)

Spam complaints

All Tools

DKIM Checker DKIM Key Generator SPF Validator SPF Record Builder DMARC Checker DMARC Generator Blacklist Checker Header Analyzer MX Lookup PTR Lookup Email Validator TXT Record Lookup BIMI Checker Subject Line Tester Bounce Rate Calc List Hygiene Calc Domain Health Check

Need infrastructure?

Tools diagnose. Dedicated infrastructure fixes the problem.

Talk to us

Email Bounce Rate Calculator: Measure Deliverability Health

Bounce rates and complaint rates are the two most actionable deliverability metrics. They directly influence whether ISPs throttle or block your sending, whether your ESP suspends your account, and whether your IP reputation deteriorates over time. This calculator helps you understand where you stand against industry thresholds.

ISP Thresholds: The Lines You Cannot Cross

Metric	Good	Warning	Critical
Hard bounce rate	< 1%	1–2%	> 2%
Soft bounce rate	< 3%	3–5%	> 5%
Spam complaint rate	< 0.08%	0.08–0.3%	> 0.3%

How to Reduce Bounce Rates

Immediately suppress all hard bounces — Never re-send to an address that hard-bounced. Most ESPs do this automatically; verify your suppression list is active.
Validate addresses before adding to your list — Use the Email Syntax Validator and consider real-time validation at signup forms.
Remove stale contacts — Use the List Hygiene Calculator to identify inactive segments to suppress before sending.
Check your sending IP — High soft bounce rates can indicate IP blacklisting or rate-limiting by receiving servers.

Bounce Rate Calculator

Bounce Rate Calculator

Email Bounce Rate Calculator: Measure Deliverability Health

ISP Thresholds: The Lines You Cannot Cross

How to Reduce Bounce Rates

INFRASTRUCTURE

OPERATIONAL NOTES

The Hidden Cost of Retry Pressure in High-Volume SMTP Systems

Inbox Placement Is a Lagging Indicator

What Breaks First When Volume Increases Too Fast

Why Shared IP Pools Fail at Scale

Separating Cold, Bulk, and Transactional Traffic at the Infrastructure Level

When NOT to Warm an IP

Contact Us