Guides
Deliverability guides and product notes — no filler.
Clean your ActiveCampaign list: unsubscribe or delete?
ActiveCampaign bills per contact, so cleaning forces a choice: unsubscribe or delete each dead address. Which lowers your bill depends on your account.
How to clean your Brevo list
What Brevo blocklists automatically, the addresses it can't catch, and how to verify and blocklist the rest before your next campaign.
How to clean your HubSpot list and cut marketing contacts
Set dead contacts to non-marketing to lower your HubSpot bill, plus the export, verify, act loop that finds which addresses to pull first.
How to clean a Mailchimp list without paying for dead contacts
Archive—don't delete—dead Mailchimp contacts to drop under an audience-tier price, plus how often to re-clean and the verify-and-archive loop.
Free vs paid email verification: what free can't tell you
Free email checkers rule addresses out; only paid verification confirms a live mailbox. Exactly where the line falls, and when each one is the right tool.
How to clean a Klaviyo list: what to suppress vs delete
Map every Qualisend verdict to a Klaviyo action: what to suppress vs delete, how Klaviyo's soft-bounce suppression works, and the export-verify loop.
Role, disposable, and free email addresses: send or suppress?
Role, disposable, and free are three verifier flags that call for three different decisions. How to tell them apart and what to do with each.
What is a catch-all email? The honest guide
Catch-all domains accept mail for any address, so no verifier can confirm a mailbox exists. What that means, why tools disagree, and how to send safely.