MailCull blog: field notes on email deliverability and list quality
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.
SPF, DKIM, and DMARC Setup: A Practical Guide With Real DNS Records
The three records, real examples, and the safe rollout sequence.
Role-Based Email Addresses: What They Are and When to Mail Them
A role-based address isn't automatically bad. It just behaves differently than a personal one, and the right call depends on what you're sending.
MX Record Validation: What It Actually Tells You About an Email Address
If the domain has no MX, no mail lands. But a healthy MX record proves less than people think. Here is where the signal stops being decisive.
How to Reduce Your Email Bounce Rate: The Complete 2026 Guide
Bounce rate is a single number with five different causes underneath. Here's how to find yours and fix the right one.
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