How to Fix Low Email Deliverability
Upload the list or connect your CRM, and Cleanlist AI verifies the emails and refills stale or missing fields from 25+ providers before your next send.
Cleanlist AI validating last-campaign-bounces.csv. Each address is marked Verified, Likely valid, Risky, Invalid or Unknown. Of 10,000 rows, 8,612 Verified, 604 Likely valid, 431 Risky, 287 Invalid, 66 Unknown.
10,000+ users, from founders to full sales teams
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How does Cleanlist AI fix low email deliverability?
Cleanlist AI attacks low deliverability at the data layer, the foundation that most deliverability tools overlook. Mailgun and SendGrid handle the sending side. Cleanlist AI checks the addresses you send to: an SMTP check on every one, plus flags for catch-all domains, disposable addresses, role-based inboxes and known spam traps. Fewer bounces and fewer complaints are what inbox providers reward, and data problems like these cause 60-70% of deliverability issues (Validity, 2025).
Why this is hard to do by hand
Your emails can avoid bouncing and still never reach the inbox. Validity's 2025 Deliverability Benchmark puts the average B2B sender at 79.6% inbox placement, so about 1 in 5 emails goes to spam or gets blocked. The causes stack up: unverified lists that bounce and hurt your sender reputation, complaints from role-based and shared inboxes, missing SPF, DKIM or DMARC records, and Google and Microsoft filters that judge your sending behavior over weeks of mail.
60-70% of deliverability problems start with the list
Teams fixing low deliverability usually start with infrastructure: SPF records, DKIM, IP warming, ESP settings. Those matter. Validity's 2025 Deliverability Root Cause Analysis of 1,200 B2B senders still traced 60-70% of problems to the data. Invalid addresses causing bounces accounted for 35% of issues, catch-all domains that look deliverable and still hurt reputation for 18%, spam traps from bought lists for 9%, and role-based addresses (info@, sales@) drawing spam complaints for 8%. Infrastructure explained the other 30-40%. So most teams are adjusting the wrong settings first. Clean the list before the next campaign, and look at infrastructure if placement is still low.
What a lookup costs
Each lookup walks 25+ providers in cost order, and you're charged once for what comes back: 1 credit for a verified work email, 10 for a phone number, 11 for both. Validation is 0.5 and AI qualification is 5. A lookup that finds nothing is free, and the whole team pays from one wallet.
- Verified work emails25 leads searched23 × 123
- Phone numbersVerified before anyone calls18 × 10180
- Qualification agentFit score with reasons25 × 5125
- 25+Providers queried in cost order on a single lookup
- 98%Verified work emails on our 500-lead benchmark
- 85%Phone numbers found on that same benchmark
- 0Credits for a lookup that finds nothing
How it works.
- 01
Audit your list's deliverability risk
Upload your list (a CSV export from your ESP works). Cleanlist AI sorts every address into deliverable, risky (catch-all, role-based) or invalid.
- 02
Find the root cause
Separate data problems from infrastructure ones. Lots of invalid, catch-all or spam-trap addresses means the list is the problem. A clean list that still lands in spam points to SPF, DKIM, DMARC or IP reputation.
- 03
Remove the bad addresses
Drop the invalid addresses and known spam traps. Catch-all domains, disposable addresses and role-based ones (info@, sales@) are flagged, so you decide how to handle each group.
- 04
Segment by engagement and risk
Send to verified, engaged contacts first to build good sender signals, then widen to the less engaged segments over time.
- 05
Validate at the point of entry
Put Cleanlist AI's verification API behind your signup forms, landing pages and imports. Invalid and disposable emails get turned away before they're saved.
- 06
Track inbox placement
Re-verify monthly to catch addresses that went bad since the last clean. Watch bounce rate, complaint rate and inbox placement in your ESP, and aim for 95% placement or better.
What you get.
Check the whole list
Validation is 0.5 credits per email, so you can run every record before a send.
25+ providers per lookup
When one provider has nothing for a contact, the waterfall asks the next one.
Fixes land in your CRM
HubSpot and Salesforce sync both ways on Pro and Enterprise, so corrected fields go back onto the same record.
A miss costs nothing
You pay for the emails and phone numbers the waterfall finds. Rows it can't fill cost 0 credits.
Manual process vs Cleanlist AI.
| Feature | Manual | Cleanlist AI |
|---|---|---|
| Root cause identification | Guesswork based on ESP metrics | An address-level audit shows whether the list is the problem |
| Spam trap detection | Not possible with standard tools | Known spam traps flagged |
| Catch-all domain handling | Invisible (counted as valid by ESPs) | Detected and flagged as risky |
| Disposable email filtering | Basic domain blocklist | Flagged on every address |
| Time to improve deliverability | 4-8 weeks of trial and error | One pass to clean, then a few weeks of clean sending |
| Preventive validation | None (bad data enters freely) | API validation on forms and imports |
How accurate is Cleanlist AI's data?
Cleanlist AI returned 98% verified work emails and 85% phone numbers on our 500-lead benchmark, pulling from 25+ data providers. Each lookup stops at the first deliverable result, meaning a verified or likely-valid email.
What do I get when I sign up?
A 14-day Pro trial: 250 credits, 3 seats, and every Pro feature. After it, the Free plan gives you 50 credits a month. A verified work email costs 1 credit, a phone number 10, and a miss nothing.
What data providers does Cleanlist AI use?
Cleanlist AI runs a waterfall across 25+ B2B data providers. For each record it asks one, moves to the next when that one has no match, and stops at the first deliverable result.
Can I connect my CRM?
Yes. HubSpot and Salesforce sync both ways on the Pro and Enterprise plans, and Salesloft and Lemlist take a one-way push. You can also upload a CSV, or use the REST API from Pro.
Will this prevent the problem from recurring?
A one-off cleanup won't, because people keep changing jobs. Re-run the list through Cleanlist AI before each campaign. Validation is 0.5 credits per email, and a lookup that finds nothing costs nothing.
What causes low email deliverability?
A dirty list, weak infrastructure and poor sending habits. The list is the biggest, behind 60-70% of deliverability issues (Validity, 2025), because invalid, catch-all and spam-trap addresses cause bounces and complaints. Infrastructure means missing or broken SPF, DKIM and DMARC records. Habits means uneven volume and high complaint rates. Cleanlist AI handles the list.
How long does it take to fix email deliverability?
The list clean takes minutes. Reputation takes longer: with a 2-5% bounce rate, expect 2 to 3 weeks of clean sending, and with bounces above 5% or spam trap hits, 4 to 8 weeks. During recovery, send only to your most engaged verified contacts and raise volume slowly.
What is a good email deliverability rate?
95% inbox placement or better. That is where the top B2B senders sit in Validity's 2025 data, against an industry average of 79.6%. Below 80%, you are losing a fifth or more of your email reach, and the list is the first place to look.
Describe the job once. An agent runs it every week.
Clu turns one sentence into an agent. It searches 1B+ profiles, finds verified emails and phone numbers across 25+ providers, adds the people to your sequence and posts each run to Slack.
Weekly ICP outbound
Built by Clu from: “Every week, find 500 new people who match my ICP, get their emails and phones, and add them to Series B outbound.”
- Searched 1B+ profiles for new ICP matches500 foundPeople Search
- Ran the waterfall across 25+ providers487 emails · 412 phonesWaterfall
- Verified every email and phoneSMTP + catch-allVerification
- Added them to Series B outbound500 peopleSequences
- Posted the run to #pipelineSlackAgents
Friday 4:52 PM15 replies · 5 calls booked
Everything in the 14-day Pro trial
- Clu and agentsDescribe the job in one sentence. Clu builds the agent, runs it on a schedule or a CRM trigger and posts every run to Slack.
- People and Company SearchFind your buyers in 1B+ profiles from one sentence. Searching costs 0 credits.
- Waterfall enrichmentAsk 25+ providers in order and stop at the first verified email or phone number. 98% verified work emails and 85% phone numbers on a 500-lead benchmark.
- Email verificationRun SMTP and catch-all checks on every address before it reaches a sequence, at half a credit an email.
- ICP scoringScore every lead 0 to 100 against your ICP, with the reasons written down. The Research and Qualification skills do the digging.
- SequencesSend email from your reps' own inboxes, with call tasks. A reply stops the sequence. Sending costs 0 credits.
- CRM syncTwo-way sync with HubSpot, Salesforce and Pipedrive. Push finished lists to Outreach, Salesloft and Lemlist.
- Chrome extensionGet a verified email and phone number in one click on LinkedIn, Sales Navigator, Salesforce and HubSpot.
- MCP and APIRun the same search and waterfall from Claude or ChatGPT with 36 MCP tools, or from your own code with the REST API.
14 days of Pro, free: 250 credits, 3 seats, agents, Sequences and Clu in Slack. Then Free at 50 credits a month, or Starter at $49 and Pro at $89 a seat a month.
Hand the job to an agent.
Upload a CSV or connect HubSpot, Salesforce or Pipedrive, and run it on your own data today.
14 days of Pro, free.
Get 14 days of Pro, free.
250 credits and 3 seats. Sign up with your work email for 100 more.