MailCull blog: field notes on email deliverability and list quality

How to Validate Email Address Format

What email syntax really allows, why most regex is wrong, and where format checking stops.

June 23, 20262 minemail-validation

How to Check Email Deliverability for a Domain

The five signals that decide whether your mail lands, and how to check them in one pass.

June 22, 20262 mindeliverability

How to Check if a Domain Is Catch-All

Why catch-all domains defeat naive verification, and how to detect them honestly.

June 21, 20262 minemail-validation

How to Clean Your Email List in Mailchimp

The complete Mailchimp list-cleaning workflow: what to verify, why SMTP probing matters, and how to act on the results.

June 20, 20265 minmailchimp

How to Detect Disposable Email Addresses

Why disposable addresses fool naive validation, and how to catch them before they pollute your list.

June 20, 20262 minemail-validation

How to Check a DMARC Record (and What the Policy Means)

Read your DMARC policy, understand none vs quarantine vs reject, and check it in seconds.

June 19, 20262 mindeliverability

How to Check a DKIM Record (and Why It Fails)

Find your DKIM selector, read the key, and figure out why signing is failing.

June 18, 20262 mindeliverability

How to Clean Your Email List in Klaviyo

A complete Klaviyo list-cleaning workflow: what verification actually covers, how to handle results, and when to do it.

June 17, 20264 minklaviyo

How to Check Your SPF Record (and Fix Common Errors)

Read your SPF record the way a receiving server does, and catch the errors that cause soft fails.

June 17, 20262 mindeliverability