How is the Sender Health Score calculated?
Purpose
The Health Score on each email sender is a single number (0–100%) that summarizes deliverability risk from recent sending, domain authentication, and sender status. This article explains how SuperSend calculates that score, what each range means, and how to improve it.
This score is not the same as warming health on the Warming dashboard (inbox rate and warming-network signals). For warming-specific health, see Understand Sender Health.
Prerequisites
- At least one email sender connected under Senders.
- Permission to view sender details.
Where to See the Health Score
- Senders → Mailboxes table → Health Score column.
- Senders → open a sender → Domain & Sender Health panel (large Health Score percentage with See how it's calculated).
SuperSend recalculates scores during automated sender health checks (typically daily). The score uses a 30-day rolling window for bounce data.
What the Score Measures
The health score is a weighted average of three components:
Component | Weight | What it reflects |
|---|---|---|
Bounce rate | 50% | Invalid-recipient bounces vs. emails sent in the last 30 days |
Domain health | 25% | Email deliverability DNS checks on the sending domain |
Sender status | 25% | Whether the mailbox is connected and in good standing |
Formula:
Health Score = (Bounce points × 50%) + (Domain points × 25%) + (Status points × 25%)
Each component is scored 0–100 points before weighting. The result is rounded to a whole percentage.
1. Bounce Rate (50% Weight)
What counts as a bounce
Only invalid recipient bounces affect this score — addresses that do not exist, domains that do not accept mail, and similar list-quality failures. Policy bounces (blocked by recipient policy) and temporary bounces are tracked elsewhere (for example Bounce Insights) but do not reduce the health score.
This matches the Bounce Rate shown on the sender’s Domain & Sender Health panel and the bounce rate on the Senders table.
Time window
Bounces are measured over the last 30 days of outbound email sends from that sender.
Minimum send volume
If the sender has sent fewer than 100 emails in that 30-day window, the bounce component is capped at 90 points so new or low-volume senders are not unfairly penalized by one or two bounces. The UI may show Early signal when volume is still low (under 50 sends).
If there were no sends in the window, the bounce component is treated as perfect (100 points).
Bounce rate → points
Invalid-recipient bounce rate (30 days) | Bounce component points |
|---|---|
Below 0.5% | 100 (excellent) |
0.5% – under 1% | 85 (good) |
1% – under 2% | 70 (acceptable for cold email) |
2% – under 3% | 55 (warning) |
3% – under 5% | 40 (elevated — needs attention) |
5% – under 10% | 25 (high risk) |
10% or higher | 0 (critical) |
Industry context: many providers review accounts around 5% bounce rate and pause sending around 10%. Keeping invalid-recipient bounces well below 2% protects both the score and deliverability.
2. Domain Health (25% Weight)
Domain health reflects email deliverability checks on the sender’s domain:
- DNS resolution
- SPF record
- DKIM record
- DMARC record
- MX record
- Blacklist status (including critical listings such as Spamhaus DBL)
Score: (passed deliverability checks ÷ 6) × 100
HTTP and HTTPS website checks are shown for information only; they do not change the health score.
Special cases:
- Inactive domain — domain health component is 0.
- Listed on Spamhaus DBL — domain health component is 0 regardless of other checks. The sender may stay active, but warming can be disabled until the listing is resolved.
New domains may show Setup in progress for up to 48 hours while DNS propagates; failed checks during propagation can lower domain health until records are fully live.
3. Sender Status (25% Weight)
Status | Status component points |
|---|---|
OK (connected, healthy) | 100 |
Other / unknown | 50 |
Invalid domain or Blacklisted | 0 |
Reconnecting a disconnected sender and fixing domain issues restores status points on the next health check.
What Score Ranges Mean
Health score | Typical meaning | Suggested action |
|---|---|---|
90–100 | Strong — bounce, domain, and status are in good shape | Safe to use in campaigns at planned volume |
75–89 | Good — minor issue in one area | Monitor bounce rate and DNS; avoid aggressive scaling |
50–74 | Moderate — meaningful issue in bounce rate or domain checks | Investigate Bounce Insights and Email Deliverability on the sender; fix DNS or list quality |
25–49 | Poor — serious deliverability risk | Reduce or pause campaign volume from this sender until fixed |
Below 25 | Critical | SuperSend may automatically disable the sender when the score stays this low, the domain is inactive, or status is invalid domain |
Very low health scores, combined with critical domain or status problems, trigger notifications and can disable sending to protect your reputation.
Example Calculations
Healthy sender
- Bounce rate 0.3% → 100 points
- Domain 6/6 checks pass → 100 points
- Status OK → 100 points
- Score: (100×0.5) + (100×0.25) + (100×0.25) = 100%
Moderate issues
- Bounce rate 2.5% → 55 points
- Domain 5/6 checks pass → 83 points
- Status OK → 100 points
- Score: (55×0.5) + (83×0.25) + (100×0.25) ≈ 73%
New sender (low volume)
- 50 sends in 30 days, high bounce rate → bounce component capped at 90
- Domain 6/6 → 100
- Status OK → 100
- Score: (90×0.5) + (100×0.25) + (100×0.25) = 95%
How to Improve Your Health Score
- Improve list quality — Use email validation before campaigns; remove invalid addresses; tighten suppression lists. Invalid-recipient bounces are half the score.
- Fix DNS — On Senders → sender → Domain & Sender Health, resolve any failing Email Deliverability checks (SPF, DKIM, DMARC, MX). See Domain Setup and DNS Checklist if your team manages DNS externally.
- Resolve blacklist listings — If the domain is on Spamhaus DBL or another critical list, remediate with your DNS/hosting provider before scaling sends.
- Keep the sender connected — Re-authenticate Gmail, Outlook, or SMTP senders if status is no longer OK.
- Ramp volume gradually — Avoid sudden spikes on mailboxes with few sends; let at least 100 sends accumulate so bounce rate reflects real performance.
- Review Bounce Insights — Open Bounce Insights on the sender to see invalid vs. policy vs. temporary failures and fix the dominant failure type.
Expected Result
You can read any sender’s Health Score and understand which factor (bounces, domain checks, or status) is driving it, interpret whether the score is healthy or at risk, and take targeted steps to raise it before deliverability or automatic disabling is affected.
Troubleshooting
- Issue: Health score is high but campaigns still land in spam.
Fix: Health score does not measure inbox placement. Run a placement test and review warming health separately.
- Issue: Bounce rate looks low but health score dropped.
Fix: Check Email Deliverability failures, sender status, or whether bounces are invalid recipient only (other bounce types do not count toward this score).
- Issue: Score stuck around 90–95% on a new sender.
Fix: Expected when send volume is under 100 in 30 days — bounce component is capped until more data exists.
- Issue: Sender was disabled automatically.
Fix: See Disabled Sender Troubleshooting. After fixing DNS, bounces, or connection, health checks can re-enable the sender when the score and status recover.
Related Articles
- Understand Sender Health — Warming dashboard health and inbox rate
- Sender Statuses and What They Mean
- Domain Setup and DNS Checklist
- Disabled Sender Troubleshooting
- Email Validation in SuperSend
Updated on: 04/06/2026
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