What it means for sendersCredentials stolen by CastleRAT from about 179,700 email addresses can now be checked in Have I Been Pwned, so teams can find out whether staff...
The encyclopedia of email
Everything you need to send email that lands
Protocols, deliverability, verification and platforms, written by practitioners and checked against official sources.
260 provider settings94 SMTP error codes72 RFCs49 blocklists
Platform finder
Find your email platform in 30 seconds
Real prices at your list size, side by side. Pick what you send:
Recommended tools
How we pick →Latest from the newsroom
All news →What it means for sendersAbout 807,000 Giants fan club members may now receive phishing that uses the club's name, and real club emails will compete with fakes in the same...
What it means for sendersUp to 1.13 million people who applied for a Monex account may now receive phishing that uses the Monex name, and brands in Japanese finance can...
New · Free WordPress plugin
SMTPing Email Suite: SMTP, newsletter and email verification in one plugin
12 mailers, email log, backup connection, forms, automations and a recipient check before every send. 1.5 MB and 100% free.
Email settings
All providersFree tools
Tool directoryBest email platforms for...
All top picksCurrent deals
Compare prices
Upcoming events
Full calendarExplore by topic
Email verificationValidate addresses before you send: bounces, disposables, spam traps.78 articlesDeliverabilityInbox placement, blocklists, warm-up, bounces and compliance.323 articlesStandards and protocolsRFCs, SMTP codes, SPF, DKIM, DMARC, DNS records and MTAs.202 articlesMarketing platformsPricing breakdowns, reviews and comparisons of email tools.53 articlesSMTP error codesEvery reply code with causes, fixes and provider notes.94 articlesEmail settingsSMTP, IMAP and POP3 settings for providers worldwide.260 articles