MailCull blog: field notes on email deliverability and list quality
Re-Engagement Campaigns: Winning Back Inactive Subscribers Without Wrecking Deliverability
You are about to mail the riskiest segment you own. Do it in this order.
You Inherited a Purchased Email List. Now What?
Verification tells you the addresses work. It cannot tell you that you may mail them.
Email List Decay: How Fast Your List Rots and What to Do About It
Roughly 2% a month, but the range is wide and the drivers are predictable.
Bulk Sender Requirements in 2026: What Gmail, Yahoo and Microsoft Now Enforce
The 0.3% spam ceiling is the rule everyone quotes. The list-hygiene requirement is the one that catches people.
The Real Cost of a Dirty Email List (With the Actual Math)
Four costs, three of them invisible. Here is the arithmetic.
Why Are My Emails Bouncing? A Diagnostic Walkthrough
The bounce report has the answer. You just need to read the codes.
What Is a Spam Trap? Types, Risk, and How to Stay Off Blacklists
Pristine, recycled, typo: three types of spam trap, three different signals about your list hygiene.
What Is a Disposable Email Address? (And Why They Distort Your List)
A disposable address isn't a fake address. It's a real one nobody's ever going to read.
What Actually Happens When You Send to an Invalid Email Address
One bad address doesn't just bounce. It nudges every subsequent send a little closer to the spam folder.
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