Verifly blog
Email deliverability & verification guides
Practical, in-depth guides on getting your email into the inbox — from authentication and bounce rates to spam traps, catch-all domains, and warming up a fresh cold-email domain. Written by the team behind the Verifly verification API.
The Complete Email Deliverability Guide (2026)
A practical, end-to-end guide to email deliverability in 2026: authentication (SPF, DKIM, DMARC), sender reputation, list hygiene, engagement signals, and the exact steps to land in the inbox instead of spam.
Read guideHow to Reduce Your Email Bounce Rate: A Practical Playbook
Hard bounces, soft bounces, and the reputation damage they cause. A step-by-step playbook to diagnose why your email bounces and drive your bounce rate back under 2%.
Read guideWhat Is a Catch-All Email — and How Should You Handle It?
Catch-all (accept-all) domains accept mail for any address, which makes mailbox verification impossible. Learn what catch-all means, why it is risky, and how to decide whether to send.
Read guideEmail Spam Traps Explained: Types, Risks, and How to Avoid Them
Pristine traps, recycled traps, and typo traps — what they are, how they get onto your list, the reputation damage they cause, and the list-hygiene practices that keep you clear of them.
Read guideHow Email Verification Actually Works: Syntax, MX, SMTP & Catch-All
A technical walkthrough of the email verification pipeline: syntax parsing, MX record lookup, the SMTP handshake, catch-all detection, and disposable and role classification.
Read guideRole-Based Emails (info@, support@, sales@): Should You Send to Them?
Role-based addresses go to teams and inboxes, not individuals. Learn why they carry higher complaint risk, when it is fine to mail them, and how to filter them from cold-outreach lists.
Read guideDisposable & Temporary Emails: Why They Wreck Your List (and How to Block Them)
Disposable and temporary email addresses inflate signups, poison analytics, and enable abuse. Understand how they work, the damage they do, and how to detect and block them at signup.
Read guideHow to Warm Up a New Cold-Email Domain Without Landing in Spam
A week-by-week domain warm-up plan: separate domains, authentication, volume ramp, engagement seeding, and list verification — the discipline that keeps a fresh cold-email domain out of spam.
Read guideEmail Bounce Codes Explained: Hard vs Soft Bounces (and What to Do)
A field guide to email bounce codes: what the 4xx and 5xx SMTP reply codes actually mean, how to tell a hard bounce from a soft bounce, and the exact action to take for each.
Read guideSPF, DKIM & DMARC: The Complete Email Authentication Setup Guide
A step-by-step guide to setting up SPF, DKIM, and DMARC correctly: what each record does, the exact DNS entries to publish, how alignment works, and how to roll out DMARC enforcement safely.
Read guideHow to Clean an Email List: A Step-by-Step Guide
A practical, repeatable process for cleaning an email list: deduplicate, fix syntax, verify deliverability, segment by risk tier, remove unengaged contacts, and keep it clean going forward.
Read guideEmail Validation vs Email Verification: What’s the Difference?
Validation and verification sound interchangeable but solve different problems. Learn what each one actually checks, why validation alone is not enough, and how to use both together.
Read guideWhy Your Emails Go to Spam (and How to Fix It)
A diagnostic guide to spam-foldering: the authentication, reputation, list-quality, engagement, and content problems that cause it, in the order to check them, with a concrete fix for each.
Read guideDouble Opt-In vs Single Opt-In: Which Is Better for Deliverability?
The trade-offs between single and double opt-in for list growth, list quality, and deliverability — and how pairing opt-in with real-time verification gets you the best of both.
Read guideHow to Choose an Email Verification API: 9 Things That Actually Matter
A buyer’s guide to email verification APIs for developers: accuracy, catch-all honesty, latency, bulk handling, pricing model, data privacy, and the integration details that separate a good API from a frustrating one.
Read guideGreylisting Explained: Why Some Emails Are Delayed (and How Verification Handles It)
Greylisting deliberately delays mail from unknown senders as an anti-spam tactic. Learn how it works, why it delays your email, how it interacts with verification, and what it means for your bounce handling.
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