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MailCull

MailCull blog: field notes on email deliverability and list quality

2026 9 of 67

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.

August 31, 20268 mindeliverability

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.

August 28, 20266 mindisposable-email

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.

August 25, 20267 mindeliverability

SPF, DKIM, and DMARC Setup: A Practical Guide With Real DNS Records

The three records, real examples, and the safe rollout sequence.

August 22, 20267 mindeliverability

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.

August 19, 20266 mindeliverability

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.

August 16, 20267 minemail-validation

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.

August 13, 20268 minbounce-rate

How to Clean an Email List: The Complete Practical Guide

Eight steps. One sitting. The list you start with isn't the list you should send to.

August 10, 202610 minlist-cleaning

How to Check if an Email Address Is Valid (Step by Step)

One address or ten thousand, the right method depends on what you're going to do with the answer.

August 7, 20265 minverify-email
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