Deliverability
Email verification guides, deliverability tips, and best practices.
SMTP Email Verification: How We Actually Check If an Inbox Exists
Behind the scenes of SMTP email verification — MX lookup, RCPT TO probes, catch-all detection, greylisting, and why we never charge for inconclusive results.
Protect Your Sender Reputation Before Your Next Email Campaign
A pre-campaign deliverability checklist — verify lists, block catch-all sends, manage suppressions, and use preflight reports so your next campaign doesn't damage domain reputation.
What Is Over Quota Email Status? Mailbox Full vs Bounce Explained
Over quota means the mailbox exists but is full — not invalid, not catch-all. Learn how SMTP 552 responses work, when to retry, and why over_quota is a billable definitive result.
Email Verification vs Email Validation: What is the Difference and Why It Matters (2026)
Confused between email verification and email validation? Learn the technical difference, when to use each, and how a combined approach protects your sender reputation and marketing ROI.
How to Warm Up an Email Domain and IP Address: The 2026 Complete Guide
Learn how to properly warm up a new email domain and IP address with a week-by-week schedule, avoid spam folder placement, and build a strong sender reputation from day one.
Email Bounce Rate: What's Normal & How to Fix It (2026 Guide)
Learn what bounce rate is normal for email marketing, the difference between hard and soft bounces, and actionable steps to reduce your bounce rate below 2%.
DKIM, SPF, and DMARC: The Complete Email Authentication Guide for 2026
Learn how DKIM, SPF, and DMARC work together to protect your domain from spoofing, improve email deliverability, and build trust with inbox providers — with step-by-step setup instructions.
Disposable Email Addresses: The Complete 2026 Guide
Everything you need to know about disposable email addresses (DEAs) — how to detect them, which domains to block, and why traditional blocklists fail against the 10,000+ temporary email services active today.
Why Catch-All Addresses Should Never Be in Your Outreach List
Catch-all domains pass SMTP checks but often hard-bounce later. Learn why valid-only outreach rules protect your sender reputation and how to handle catch-all results correctly.
Catch-All Email Explained: Should You Send or Skip? (2026)
What is a catch-all email server, how to detect catch-all domains, and the data-driven approach to deciding whether to send to catch-all addresses or remove them from your list.