Blog
Insights, guides, and best practices for email verification
What is a Disposable Email Address? A Guide to Blocking Fake Users
Disposable emails let one person register an account hundreds of times. Why might this be devastating for your business?
What is a High Bounce Rate? Meaning, Benchmarks, Reasons and How to Fix It
A high bounce rate costs you money and hurts your sender reputation. Learn what it means, how to benchmark it, and how to fix it.
How To Stop Free Trial Abuse
Free trials drive conversions — but they also invite abuse. Learn how to identify and stop users who exploit your free tier before it hurts your bottom line.
Secure Signup Forms Checklist: How to Protect Your Registration Process
An unprotected signup form is an open door for bots and scammers. This checklist walks through every layer of defense — from frontend validation to backend monitoring.
B2B Email Verification: How to Improve Deliverability and Conversion
Clean B2B email lists lead to fewer bounces, a stronger sender reputation, and more replies. Learn how email verification directly improves deliverability and conversion.
Catch-all email verifier: how to actually validate accept-all domains
Standard email checkers mark catch-all addresses as valid because the receiving server says yes to every probe. A real catch-all verifier combines SMTP signals with domain-level data.
What is a catch-all email address?
A catch-all domain accepts mail to every address at the domain — even mailboxes that were never created. SMTP returns 'valid' for all of them, which is technically true and operationally useless.
What is a disposable email address?
Roughly 12% of public-form signups now come from disposable emails. Here's how the services work, who uses them, and what they cost a business.
How to check if an email is disposable
Match the domain against a maintained list of known disposable providers. Three approaches use that method at different points in the signup flow — open-source, API, or built-in form validation.
Soft bounce vs hard bounce: every difference that matters
Hard bounces are permanent — address doesn't exist or server refused. Soft bounces are temporary — full inbox, server timeout. Hard requires suppression; soft usually retries on its own.
Why do emails bounce? 9 real causes and how to fix each
Bounces happen when the receiving mail server refuses delivery. The cause determines the fix — invalid address, dead domain, full inbox, blocklisting, greylisting, or reputation collapse.
How to check if an email is disposable
Match the domain against a maintained list of known disposable providers. Three approaches work at different points in the signup flow: open-source list lookup, API call, or built-in form validation.
Why do emails bounce? 9 real causes and how to fix each
Emails bounce when the receiving server refuses delivery. Hard bounces are permanent (invalid address, dead domain); soft bounces are temporary (full inbox, rate limit). The cause determines the fix.
Email scrubbing: how to clean a list without losing the subscribers worth keeping
Email scrubbing removes invalid, inactive, and risky addresses from a marketing list. Scrubbing covers verification plus engagement filtering — a smaller list that delivers more reliably.
Email list cleaning service: what it does, when to use one, and what to evaluate
An email list cleaning service runs each address through syntax check, MX lookup, SMTP probe, and reputation matching, then returns addresses labeled valid, risky, or invalid.
Email deliverability consultant: when to hire one
A deliverability consultant diagnoses why your mail lands in spam, then prescribes fixes — DNS auth, IP warmup, reputation rehab, list hygiene. Most useful when the basics are done and placement still won't cross 80%.
Email deliverability tools: the six categories that actually move inbox placement
The deliverability stack has six job categories: list verification, authentication monitoring, inbox-placement testing, reputation monitoring, ESP-side reporting, and remediation tooling. No single tool covers all six.