Writing that delivers.
Deliverability guides and product notes — no filler.
How to clean an AWeber email list and cut the bill
Clean your AWeber list: export, verify, and prune the dead subscribers you pay for — cut your bill and protect deliverability.
How to clean a Campaign Monitor email list
Campaign Monitor auto-suppresses bounces and unsubscribes but can't vet never-mailed imports. Use the export, verify, act loop to clean your list.
The best Kickbox alternatives in 2026, compared
Looking for a Kickbox alternative? EU and lower-priced verifiers compared on data residency, scoring, and catch-all honesty — with sourced facts.
How to clean a Drip email list
Drip suppresses bounces and unsubscribes automatically, but not the dead never-mailed addresses on your bill. Here's how to clean a Drip list.
How to clean your Customer.io list
What Customer.io suppresses on its own, the profiles it can't see, and how to verify and retire dead profiles that inflate your bill.
How to clean an EmailOctopus email list and cut your bill
EmailOctopus auto-removes hard bounces but not the invalids it never mailed. Verify your export to clean your list and trim your subscriber bill.
How to validate an email address in Python
Validate an email address in Python properly: syntax, an MX lookup with dnspython, and the SMTP mailbox probe — with working code.
How to validate an email address in Ruby
Validate an email address in Ruby in three layers: URI::MailTo syntax, a Resolv MX lookup, and an SMTP mailbox check via API, with working code.
How to validate an email address in Go
Validate an email address in Go the right way: net/mail.ParseAddress for syntax, net.LookupMX for MX, and an API for the SMTP mailbox check.
How to validate an email address in Java
Validate an email address in Java properly: syntax with Jakarta Mail, an MX lookup via JNDI, and an SMTP mailbox check — with working code.
How to validate an email address in C#
Validate an email address in C# the right way: MailAddress for syntax, DnsClient for the MX lookup, and an API for the SMTP mailbox probe.
Email blocklists (DNSBLs) explained
Email blocklists (DNSBLs) can send your mail to spam for millions of recipients at once. How they work, how you get listed, and how to check and delist.