The End of Old-School Email Verification
B2B email infrastructure has evolved; legacy verifiers haven’t. While others fail against enterprise catch-all servers and Secure Email Gateways, we provide the deep analysis required to verify them. Access the only infrastructure capable of delivering conclusive results on catch-alls and enterprise mailboxes with absolute precision.
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Designed for Corporate Filters & Catch-all Servers
Syntax, SMTP checks, and DNS & MX validations are effortless industry standards. While they work well for B2C, B2B demands more. We built our engine to solve the “hard-to-verify” reality of corporate data. When basic SMTP checks fail, our infrastructure adapts to resolve the complex catch-alls and gateways that leave legacy tools blind.
Verify Corporate Catch-Alls
Corporate servers often accept all traffic to mask user existence, causing "Unknowns". We look past this setup to deliver “Valid/Invalid” statuses that distinguish active mailboxes from non-existent users, maximizing data coverage in domains others are forced to ignore.
Solve Secure Gateways
Gateways like Mimecast greylist standard verification requests. Our infrastructure recognizes these setups and adjusts protocols to resolve the block, validating high-value contacts hidden behind the world’s toughest security filters.
Primary Email Detection
Legacy tools often return multiple valid aliases for high-level executives. We cut through the noise to identify the specific primary inbox used by the C-suite decision-maker, filtering out secondary unmonitored aliases that typically inflate and degrade B2B data quality.
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Unlimited Verifications Inside Your Tech Stack
Legacy "per-credit" models force teams to verify infrequently due to budget constraints. We've replaced this outdated pay-per-email model with unlimited verification when Allegrow is integrated directly into your workflow. Whether in your CRM, Sales Platform, or CSV uploads, you can verify every contact before each GTM action.
Automated Pre-Send Protection
Relying on manual list cleaning is a strategy for failure. Acting as an automated gatekeeper, we intercept and verify every email before it leaves Salesloft & Outreach. This ensures a contact going bad today won't damage your reputation tomorrow.
Predictable Flat Rate
Per-credit pricing punishes you for being thorough, forcing data decay to save budget. We reverse this dynamic. With a fixed, unlimited license, you are incentivized to re-verify your CRM as often as you'd like. Eliminate the choice between data quality and budget.
Natively Integrated
Allegrow directly integrates with HubSpot, Outreach, Salesloft, and more, enabling unlimited verifications across your entire system of record to reduce errors and drive results. At the same time, bulk CSV uploads are also available for any manual data flow.
Scalable and Customizable Verification API
Scale your data product without hitting a verification bottleneck. We provide the dedicated backend for modern data products and AI agents, handling the complex rotation of IPs and verification methods required to validate hundreds of millions of records. Integrate a customizable API that increases your email accuracy and new email contacts found at scale.
Granular Customization
One size does not fit all. Configure the verification engine to match your data flow. Define your preferred mix of SMTP and alternative methods, and choose between synchronous and asynchronous processing to align with your product's architecture.
Managed IP Infrastructure
Consistent access to mail servers at scale is critical for data accuracy. We manage a rotating network of high-reputation IPs to automatically resolve greylisting and rate limits, ensuring definitive, reliable verification results even at peak volume (100s of millions).
Secure & Transparent
You require a secure partner to scale. Allegrow is SOC-2 certified & audited, ICO-registered, and GDPR-compliant with Enterprise DPAs. Supporting SSO and maintaining real-time security monitoring via a Trust Center, providing enterprise-level security for your data.
Frequently Asked Questions
How is Allegrow different from standard email verifiers?
Most verifiers are generalist tools built for B2C, relying on simple SMTP checks that fail against complex B2B infrastructure. When faced with catch-all servers or Secure Email Gateways, they are forced to return inconclusive "Unknown/Accept-all" results. Allegrow is purpose-built for these B2B challenges. We reliably resolve these complex domains with absolute precision, eliminating false negatives to provide a definitive ”Valid” or “Invalid” status where legacy tools leave you guessing.
How do you solve catch-alls when others return "Unknown" or “Accept-all”?
Legacy tools rely on server responses alone, which fail on catch-alls because those servers accept everything. We supplement this by analyzing proprietary signals to detect the difference between a real active inbox and a silent re-route or a spam trap. This allows us to convert vague "Unknowns" into conclusive "Valid" or "Invalid" results.
Do you use "test emails" to verify?
Never. Sending fake emails to verify accounts is a dangerous practice that burns IPs and gives unreliable results, as many servers won't send a bounce back (NDR) even when an email is sent to an invalid inbox. A test email approach would falsely mark these as "Valid", filling your data-set with invalid contacts. We use proprietary signals to definitively confirm existence, providing higher reliability on results by eliminating the false positives associated with email-based testing.
With the new Google & Yahoo rules, is basic verification enough?
Absolutely not. The new rules strictly enforce a 0.3% spam complaint rate, while maintaining a bounce rate below 2% remains essential for inbox placement. Basic verifiers leave "accuracy gaps", particularly with catch-alls & Secure Email Gateways, which leads to spikes in both metrics. Allegrow prevents this by resolving the complex contacts legacy tools miss, ensuring your data is clean and safe
What’s unlimited and what isn’t?
Unlimited verification is available on our Scale Plus plan for internal sales teams cleaning their own proprietary data via CSV uploads or native CRM/SEP integrations. These plans operate under fair usage guidelines and include an additional allowance of 1 million API requests per month for internal automation workflows.
Verification is not unlimited on API Plans, which are designed for data providers or platforms embedding verification into their own products. These packages are priced per request/contact to support the guaranteed latency, custom rate limits, and throughput (up to 100s of millions) required to power data products.
Can you verify enterprise domains hosted by Secure Email Gateways (Proofpoint & Mimecast)?
Yes. This is a core differentiator. Enterprise domains (like those protected by Proofpoint or Mimecast) often greylist standard verification pings. Our infrastructure is specifically engineered to navigate these Secure Email Gateways, allowing you to verify high-value decision-makers at Fortune 500 companies that other tools miss.
What is "Primary Email Detection"?
Legacy tools use syntax guessing and SMTP, which returns multiple "valid" aliases for one person, even if only one is actively monitored. Allegrow uses new verification methods to identify the primary operational inbox, ensuring your message gets read rather than re-routed to an unmonitored alias or incorrect inbox.
What is your API throughput capacity?
We are built for data providers and enterprise teams verifying hundreds of millions of contacts. Whether you need synchronous results or asynchronous bulk processing, our infrastructure scales to meet your volume with custom rate limits and dedicated engineering support.
What’s the best way to benchmark catch-all verification accuracy?
We advise against simple side-by-side comparison on unknown data. Instead, we recommend building a controlled sample of ~1,000+ contacts comprising "Known Valids" (recent threads) and "Known Invalids" (synthetically generated permutations). This isolates the variable of catch-all server behavior, exposing exactly how Allegrow handles false positives and re-routes. We have open-sourced the prompts and logic for this test here: Testing Catch-All Email Verification.
What exactly happens after I request my free trial or API consultation?
You receive immediate 14-day access to the platform to verify up to 1,000 contacts, allowing you to benchmark your current lists and validate our accuracy firsthand. Simultaneously, a deliverability specialist will reach out to facilitate the next step based on your needs: either a Strategy Session to help you maximize trial value, or a Technical Deep-Dive with our engineering team to answer specific API and infrastructure questions peer-to-peer.
See What Your Current Verifier Is Missing
You are sitting on 1000s of valid emails labeled as "Unknown" or “Accept-all”. We turn those dead ends into usable data. Upload a sample of hard-to-verify enterprise accounts to see us resolve the complex domains that break standard verifiers.