Learn About Email Validation
Guides, tutorials, and best practices to help you get the most out of your email validation workflow.
The Ultimate Guide to Catch-All Emails
Everything you need to know about catch-all domains: what they are, why standard tools fail to validate them, and how Scrubby's proprietary technology delivers the answers other tools can't. Includes real-world case studies and actionable strategies.
Guides, Tutorials & More
Dive deep into email validation best practices with our curated collection of resources.
How to Validate Risky Emails
Learn the step-by-step process for validating catch-all and risky emails that standard tools mark as unknown.
Understanding Catch-All Domains
What catch-all domains are, why they matter for your email campaigns, and how to handle them effectively.
Email Deliverability Best Practices
Proven strategies to improve your email deliverability rates and protect your sender reputation across all major ISPs.
Integrating Scrubby with Your Stack
Step-by-step tutorials for connecting Scrubby with Clay, HubSpot, Instantly, SmartLead, Zapier, and more.
How to Verify Catch-All Emails
What to actually do with the addresses ZeroBounce and similar tools hand back as "unknown", and how to resolve them.
Scrubby API Documentation
Complete API reference with authentication, endpoints, webhooks, and code examples in multiple languages.
Email Verification vs Validation
Understand the critical difference between email verification and validation, and why you need both for optimal results.
Latest from the Blog
Stay updated with the latest insights on email validation, deliverability, and lead generation.
How to Audit a Purchased or Scraped B2B Email List Before You Send a Single Email
A bought, scraped or enriched B2B list arrives looking clean and labelled verified. It rarely is. Here is a step-by-step audit to run before the first send: provenance, structure, duplicates, role and trap risk, validation, and the catch-all segment that every standard check waves through.
Amit S. · Oct 26, 2026 
How Long Does Catch-All Email Verification Take?
Standard verification returns in seconds but cannot resolve catch-all addresses. On Scrubby, Quick Verification settles most of them in minutes with a catch-all probe. Deep Verification is for the rest: it sends real email and observes mail server behaviour over 72 hours, with first results in 24 hours and final results in 72 hours.
Amit S. · Oct 26, 2026 
Is It Bad to Send Cold Emails to Catch-All Addresses?
Sending unverified catch-all addresses from your main domain is risky. It is not always bad. When to verify, segment or skip them, and what verifying costs.
Nick Abraham · Oct 26, 2026 
Apple Mail Privacy Protection Broke Open Rates: How to Measure List Health Without Them
Apple Mail Privacy Protection pre-fetches and proxies tracking pixels, which means an open can be recorded for a message nobody read. That quietly ruins engagement scoring, sunset policies, and the habit of using open rate as a proxy for list health. Here is what the relay actually does, which metrics survive it, and how to rebuild list hygiene on signals that cannot be faked.
Amit S. · Oct 16, 2026 
Outlook High-Volume Sender Requirements: What SPF, DKIM, and DMARC Do Not Fix
Microsoft now requires SPF, DKIM, and aligned DMARC from any domain sending more than 5,000 messages a day to Outlook.com. Passing those three checks is the entry fee, not the finish line. Here is what the requirements actually say, how to read a 550 5.7.515 rejection, and why list quality decides what happens after you are compliant.
Kristel K. · Oct 15, 2026 
Two Validators, Two Verdicts: How to Reconcile Conflicting Email Verification Results
You ran the same list through two verification tools and got two different answers on thousands of addresses. That is not a bug in either tool. Here is how to read the disagreement, which verdict to trust in each case, and the one reconciliation rule that quietly destroys lists.
Abhinav · Oct 14, 2026 Stay Updated
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