> ## Documentation Index > Fetch the complete documentation index at: https://docs.vortexiq.ai/llms.txt > Use this file to discover all available pages before exploring further. # Bounce Rate, Dotdigital > Hard + soft bounce combined. Above 5% Dotdigital throttles to protect IP reputation. How to read it, why it matters, and how to act on it. **Metrics type:** [Key Metrics](/nerve-centre/overview#metrics-types-explained) • **Category:** [Email Marketing](/nerve-centre/connectors#connectors-by-type) > Hard + soft bounce combined. Above 5% Dotdigital throttles to protect IP reputation. ## At a glance > The share of attempted sends that the receiving mail server rejected, hard plus soft combined. **Above 5% Dotdigital's compliance team will throttle, pause, or deliverability-coach the account** to protect its shared-IP reputation. Above 8% the account risks a sending freeze. The single most important Dotdigital deliverability number; treat anything over 2% as a yellow flag and over 5% as a red one. | | | | ------------------------- | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | **What it counts** | `(numHardBounces + numSoftBounces) / numSent` per campaign or programme send, rolled up across the period. The numerator and denominator both come from `/v2/campaigns/{id}/summary` and the equivalent programme endpoint. | | **Definition of "sent"** | **Accepted by Dotdigital's outbound MTA**, before the receiving server's accept or reject decision. Each accepted send becomes one of: delivered, soft-bounced, hard-bounced, or deferred. | | **Hard vs soft split** | **Combined on this card.** Hard bounces (invalid mailbox, domain non-existent, blocked sender) are auto-suppressed permanently after 1 attempt. Soft bounces (mailbox full, server temporarily unavailable, greylisted) are retried up to 5 times across 72h, then suppressed. To split the two, drill into the campaign view in Dotdigital. | | **Spam folder placement** | **Not counted as a bounce.** A delivered-to-spam email is "delivered" from the sender's point of view; the receiving server accepted it. Inbox-vs-spam placement is invisible to the sender unless you run a dedicated seed-list test (Dotdigital partners with EmailOnAcid and Litmus for this). | | **Reputation threshold** | Dotdigital's internal compliance threshold is **bounce rate above 5% across the rolling 7-day window**. Crossing this triggers an automatic notification to the merchant's account manager and may result in throttled sending until the list is cleaned. | | **List-cleaning impact** | A re-permissioning sweep (or a CSV upload to a new list) will spike bounce rate for 24 to 72h while invalid addresses get caught, then crash back to baseline. This is normal and not a red flag. | | **GDPR re-permissioning** | Dotdigital's quarterly inactive-contact suppression sweep typically removes 15 to 25% of the file. Bounce rate spikes briefly during the sweep then settles. | | **Time window** | `30D vsP` (rolling 30-day rate vs prior 30-day) | | **Alert trigger** | `>5%`, drives the deliverability sentiment key | | **Sentiment key** | `klv_bounce_rate` (shared with Klaviyo's equivalent for cross-platform comparison) | | **Roles** | owner, marketing, engineering | ## Calculation Calculated automatically from your Dotdigital data. See the At a glance summary above for what the metric tracks and the worked example below for a typical reading. ## Worked example A UK fashion retailer running on Magento with Dotdigital for the last 4 years. List size 412,000 consented contacts. The 30-day window covers 03 Apr 26 to 02 May 26. | Metric | Value | | --------------------------- | -------------- | | Total sends in period | 1,840,000 | | Hard bounces | 22,100 (1.20%) | | Soft bounces | 18,400 (1.00%) | | **Bounce rate (this card)** | **2.20%** | What's interesting: 1. **2.20% is in the healthy band**, well below the 5% throttle threshold. Industry baseline for established UK B2C lists with active hygiene is 1.5 to 2.5% on combined hard + soft. 2. **The 1.20% hard bounce rate would have been higher** without Dotdigital's auto-suppression. Each hard bounce only counts once because Dotdigital permanently removes that contact from sendable state after the first failure. Without auto-suppression, a stale list will compound bounces send after send. 3. **The retailer ran a Boxing Day catalogue upload on 26 Dec 25 that imported 38,000 contacts from a 2023 in-store loyalty CSV**. For the first 3 sends in early January, bounce rate jumped to 6.8%. The Dotdigital deliverability team flagged the account, suggested running the file through Dotdigital's Email Validation tool (which costs £0.005 per address), and bounce rate dropped back to 2.1% by 09 Jan 26. **CSV uploads are the single biggest cause of unexpected bounce-rate spikes.** 4. **Soft bounces concentrate at known free-mail providers.** Roughly 40% of the 18,400 soft bounces came from `gmail.com` (mailbox-full and greylisting), `outlook.com` (rate-limit deferrals), and `yahoo.com` accounts. These mostly get retried successfully. 5. **A 12 Apr 26 segment send to "Inactive 12m+" (62,000 contacts) bounced at 11.4%.** This is what re-engagement campaigns look like, the Dotdigital recommendation is always to re-permission first, send second. The retailer paused the rest of the segment, sent a re-permissioning campaign, and only sent the promotional follow-up to those who clicked the consent link. Bounce rate on the second send: 0.8%. ## Sibling cards merchants should reference together | Card | Why pair it with Bounce Rate | | ----------------------------------------------------------------------------------------------- | --------------------------------------------------------------------------------------------------------------------------------------------- | | [Dotdigital Spam Complaint Rate](/nerve-centre/kpi-cards/dotdigital/spam-complaint-rate) | The other deliverability red-line. A spike in both at once means the list itself is the problem (stale or scraped). | | [Dotdigital Delivery Rate](/nerve-centre/kpi-cards/dotdigital/delivery-rate) | The inverse view. `1 - bounce_rate ≈ delivery_rate` minus deferrals. | | [Dotdigital Suppressed Contacts](/nerve-centre/kpi-cards/dotdigital/suppressed-contacts) | The cumulative outcome of bounces. A rising suppression list means historic bounce hygiene worked, but the active sendable file is shrinking. | | [Dotdigital Active Subscribers Estimate](/nerve-centre/kpi-cards/dotdigital/active-subscribers) | The real reachable base after suppressions. Pair to see "how much of my list is actually deliverable". | | [Bounce Spike alert](/nerve-centre/kpi-cards/dotdigital/bounce-spike) | The detection layer for sudden moves. This card shows the trend; the alert tells you when it broke. | | [Sender Reputation alert](/nerve-centre/kpi-cards/dotdigital/sender-reputation-risk) | Bounces feed sender reputation; a sustained high bounce rate trips this alert with a 24h lag. | | [Dotdigital Open Rate](/nerve-centre/kpi-cards/dotdigital/email-open-rate) | Healthy bounce rate on a list with collapsing open rate is the spam-folder pattern; bounce rate alone won't tell you. | | [BigCommerce Newsletter Signups](/nerve-centre/bigcommerce/bc_newsletter_signups) | The supply side. A surge in low-quality signups from a paid campaign or a missing reCAPTCHA shows up here a week later. | ## Reconciling against the vendor's own dashboard **Where to look in Dotdigital:** [r1-app.dotdigital.com → Insights → Email Health](https://r1-app.dotdigital.com/insights/email-health) for the rolling deliverability view. The Email Health dashboard splits hard vs soft and shows the receiving-domain breakdown (Gmail, Outlook, Yahoo, custom MX). Also useful: [Account Settings → Email Sending Reputation](https://r1-app.dotdigital.com/account/email-sending-reputation) for the IP-pool-level view that drives Dotdigital's compliance team's decisions. For a per-campaign forensic view: *Campaigns → Reports → Campaign Summary → Detailed Statistics → Bounces*. This breaks bounces down to the individual SMTP rejection code (e.g. `550 5.1.1 mailbox does not exist`). **Why our number may legitimately differ from Dotdigital's dashboard:** | Reason | Direction of divergence | | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | ------------------------------------------------------- | | **Soft-bounce retry counting**. Dotdigital may count a soft bounce that retries successfully later in the period as "delivered" on its own dashboard but as "soft bounce + delivery" on the API summary, depending on the report variant. | Vortex IQ slightly higher on bounce rate | | **Time-zone**. The Email Health dashboard runs on account locale; Vortex IQ runs UTC. Boundary-day spikes will appear in different 30-day windows. | ±0.1 to 0.3 percentage points at the boundary | | **Region pod**. Multi-pod accounts (`r1` UK, `r2` US, `r3` AU) only count the connected pod. | Vortex IQ lower if pods exist outside the connected one | | **Suppression-list timing**. Dotdigital removes hard-bounced contacts permanently on the next send attempt; if the merchant ran a fresh CSV upload after the API pull, the dashboard will show the post-suppression list and Vortex IQ the pre-suppression. | Small drift around CSV uploads | **Cross-connector reconciliation:** Bounce rate is a definitional twin across email platforms. The metric is comparable but the *threshold* is platform-specific (Mailchimp throttles at 4%, Klaviyo at 6%, Dotdigital at 5%). | Card | Expected relationship | What causes legitimate divergence | | ---------------------------------------------------------------------------------- | ------------------------------------------------------------------ | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | [`klaviyo.klv_bounce_rate`](/nerve-centre/kpi-cards/klaviyo/bounce-rate) | Same definition (combined hard + soft), comparable rate | A merchant migrating from Klaviyo to Dotdigital often sees bounce rate jump for the first 30 days because Dotdigital's stricter soft-bounce retry policy surfaces existing list rot that Klaviyo's longer retry window had been masking. | | [`mailchimp.mc_bounce_rate`](/nerve-centre/kpi-cards/mailchimp/bounce-rate) | Same shape, slightly lower threshold (4% Mailchimp, 5% Dotdigital) | Mailchimp's compliance team intervenes one percentage point earlier. | | [`brevo_sendinblue.bs_bounce_rate`](/nerve-centre/brevo_sendinblue/bs_bounce_rate) | Same definition | Brevo also UK and EU shaped, similar GDPR profile, expect comparable rates on similar list sizes. | ## Known limitations / merchant FAQs **My bounce rate just hit 6%. Will Dotdigital actually freeze my account?** Not on the first crossing. Dotdigital's compliance team will reach out (usually via the dedicated account manager for Engagement Cloud accounts; via the `compliance@dotdigital.com` thread for self-serve). The first response is "tell us what changed". Common answers: a CSV upload, a list import from another ESP, a long-dormant account resuming sending. Resolution paths in order of preference: (1) run the file through Dotdigital's Email Validation tool, (2) re-permission inactive contacts, (3) reduce sending frequency to give the IP reputation time to recover. A second crossing within 14 days is more serious and may trigger a 24 to 48h sending pause. **Why is my bounce rate higher than my Klaviyo bounce rate was?** Two reasons, both structural. First, Dotdigital retries soft bounces only 5 times (Klaviyo retries up to 9 over 5 days), so addresses that Klaviyo eventually delivered to may bounce on Dotdigital. Second, the Dotdigital-published bounce rate combines hard + soft on a single line; Klaviyo also combines them, but the per-receiving-domain handling differs. Expect 0.5 to 1.0 percentage points higher on Dotdigital for the same list during the first 30 days post-migration; it converges as the list stabilises. **Hard vs soft, why does Dotdigital combine them on the dashboard?** Because in 2026 the receiving-server response codes have blurred. A `550 5.1.1` (mailbox doesn't exist) is unambiguously hard, but `550 5.7.1` (policy rejection) might be a hard mailbox-blocked or a soft IP-blocked-this-hour. Dotdigital normalises these into hard or soft using its own classifier, but the combined number is the one that drives the IP-reputation feedback loop, so the headline metric merges them. The split is available in the per-campaign detailed statistics. **My account just imported a 50,000-row CSV. What do I do?** Run the file through Dotdigital's [Email Validation tool](https://r1-app.dotdigital.com/account/email-validation) before sending. It costs roughly £0.005 per address (£250 for 50,000 contacts) and removes 5 to 15% of the file as undeliverable. The alternative, sending and bouncing, costs more in IP reputation than the validation fee. **A campaign to my "VIP customers" segment bounced at 8%. What's wrong?** Almost certainly stale data. VIP segments are usually built from CRM exports of high-value customers who haven't engaged with email for 6+ months. The CRM keeps the email address on file long after the contact's mailbox has been recycled, transferred to a new domain, or auto-filtered to spam. Run the segment through Email Validation, then re-permission anyone over 12 months inactive before sending promotional content. **What counts as a "soft" bounce that retries vs one that gives up?** Dotdigital retries any soft bounce up to 5 times across 72 hours, then permanently treats it as a hard bounce and suppresses. After the suppression, future sends to that contact are blocked at the queue level (they don't even reach the receiving server). Suppressions are stored on a per-account basis and exposed via [Suppressed Contacts](/nerve-centre/kpi-cards/dotdigital/suppressed-contacts). **Does Apple Mail Privacy Protection (MPP) affect bounce rate?** **No, MPP only affects open rate.** Bounces are a server-to-server signal between Dotdigital's MTA and the receiving mail server, and they happen before the email is rendered in any mail client. MPP does affect [Open Rate](/nerve-centre/kpi-cards/dotdigital/email-open-rate), where Apple's pre-fetch inflates opens, and it can indirectly affect engagement-based segmentation, which then affects who you send to, which then affects bounce rate. The chain is real but indirect. **My bounce rate is 0.8%, why is the alert still firing?** Check the [Bounce Spike alert](/nerve-centre/kpi-cards/dotdigital/bounce-spike). The headline rate may be fine but the alert detects sudden moves vs a 30-day baseline (>2σ), so a campaign that bounced at 4% in a otherwise 0.8% account will trigger even though the rolling-30D rate stays low. The spike alert is a leading indicator; this card is the trend. **Should I worry about my bounce rate per-domain?** For mature brands sending more than 500k/month, yes. Healthy per-domain bounce rates: Gmail under 1.5%, Outlook under 2.5%, Yahoo under 3.0%, custom-domain (B2B) under 2.0%. A single domain spiking to 10%+ usually means an MX or DMARC change at that ISP, not a problem with your list. The per-domain breakdown is only available in the Dotdigital UI under *Insights → Email Health*. *** ### Tracked live in Vortex IQ Nerve Centre *Bounce Rate* is one of hundreds of KPI pulses Vortex IQ tracks across Dotdigital and 70+ other ecommerce connectors. Nerve Centre runs the detection layer; Vortex Mind investigates the cause when something moves; Ask Viq lets you interrogate any number in plain English. [Start for free](https://app.vortexiq.ai/login) or [book a demo](https://www.vortexiq.ai/contact-us) to see this metric running on your own data.