--- title: "Monitor sender health & bounce rates | FirstSales" description: "Read the per-mailbox health cards in campaign analytics — warmup score and bounce rate — and know when a sender is at risk." canonical: "https://firstsales.io/tutorial/sender-health-monitoring/" --- [Home](/)/[Tutorials](/tutorial/)/Monitor sender health & bounce rates Deliverability # Monitor sender health & bounce rates Read the per-mailbox health cards in campaign analytics — warmup score and bounce rate — and know when a sender is at risk. 6 min read·Intermediate·7 steps 1. 1 ## What sender health tells you The Sender Health row shows per-mailbox **warmup score** and **bounce rate** for a campaign, so you can spot the one inbox dragging down the whole send before it costs you the domain. 2. 2 ## Open a campaign's Analytics Open a campaign and go to **Analytics**. Scroll to the **Sender Health** row. It only appears when the campaign is sending from **2 or more mailboxes** — single-sender campaigns don't show it. ![Open a campaign's Analytics](/tutorials/sender-health-01-cards.webp) 3. 3 ## Read a healthy card Each mini-card shows the sender's email, a warmup gauge, **Bounce %**, and **Sent** count. A neutral border means nothing has tripped the health checks. 4. 4 ## Spot an at-risk card A card gets a **red outline** and a red **Health issues** info icon when either threshold trips: **bounce rate above 5%**, or **warmup score below 50/100**. 5. 5 ## Open the health-issues popover Click the red info icon to see the exact issue text — for example _“High bounce rate (7.2% > 5%)”_ or _“Low warmup score (41/100 < 50)”_. 6. 6 ## Drill into a sender's emails Click a card to open that mailbox's sent-email list for the analytics date range you have loaded, so you can see exactly what went out. 7. 7 ## Act on it High bounce → clean the contact list and check Delivery Protection. Low warmup → give the mailbox more time to ramp, or pause it in this campaign until it's healthier. See the warm-up and bounce-recovery tutorials for the fixes. ## Pro tips Hard-won shortcuts that keep warm-up on track. 1 ### Add a second sender to see it The row is hidden for single-mailbox campaigns by design. If you never see it, you're running one inbox — add a second sender and it appears. 2 ### A red card is a warning, not a failure Warmup below 50 usually means "still ramping," not "broken." Give a new mailbox time before scaling its volume onto this campaign. 3 ### 5% bounce is the same line Delivery Protection uses That threshold matches the platform's own auto-pause line — treat a red bounce card as "clean the list now," not "wait and see." 4 ### Check whether bounces cluster Click into the sender's email list to see whether bounces come from one bad import batch or spread across the whole list — that changes the fix. ## Frequently asked questions Why don't I see a Sender Health row? It only renders for campaigns with **2 or more mailboxes**. Single-sender campaigns hide it. What makes a card turn red? Either the mailbox's bounce rate is above **5%**, or its warmup score is below **50 out of 100**. Can I change the health thresholds? No — they're fixed at 5% bounce and 50 warmup, matching the platform's own risk lines. What's the “warmup score”? A 0–100 measure of your mailbox's warm-up progress. Under 50 means it hasn't warmed enough to safely send campaign volume. What do I do about a high-bounce sender? Clean the contact list, verify emails, and check Delivery Protection. High bounce is what burns domains and can auto-pause a campaign. Can I click a card for more detail? Yes — each card opens that mailbox's sent-email list for the analytics date range you've loaded. ## Ready to put this into practice? Start your FirstSales trial and launch a warmed, authenticated mailbox in minutes. [Start for $1](https://app.firstsales.io) [All tutorials](/tutorial/)