// GUIDES
SMTP guides
In-depth pages for people searching about smtp — written for humans and clear enough for search and AI citation.
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20 guides
SMTP relay for transactional emailUK SMTP relay for apps and websites. Authenticated mail via mail.l9s.io with SPF, DKIM, DMARC and TLS. From £5/mo.Laravel + Layer 9 SMTPConfigure Laravel mail to use Layer 9 SMTP. HOST mail.l9s.io, port 587 STARTTLS, authenticated relay for notifications.WordPress email that actually sendsStop WordPress email failures. Connect WP Mail SMTP or similar plugins to Layer 9 SMTP for authenticated delivery.Node.js apps + Layer 9 SMTPSend email from Node.js with Nodemailer or similar via Layer 9 SMTP. TLS SMTP AUTH on mail.l9s.io.Transactional email without the dramaTransactional email for UK businesses via authenticated SMTP relay. Receipts, alerts, and user notifications that deliver.SMTP relay vs email APIUnderstand SMTP relay vs email APIs. Layer 9 SMTP uses standard SMTP AUTH — no proprietary SDK required.Authenticate before you scale sendingSet up SPF, DKIM and DMARC for Layer 9 SMTP so receiving servers trust your transactional email.Fix WordPress “email not sending”WordPress emails not sending? Switch from PHP mail to Layer 9 authenticated SMTP and verify DNS auth.Deliverability is a practice, not a sloganImprove inbox placement with authenticated SMTP, clean sending practices, and proper DNS — Layer 9 SMTP.587 vs 465 explainedUse port 587 with STARTTLS or 465 with implicit TLS on mail.l9s.io. Both supported by Layer 9 SMTP.SaaS notification email via SMTPSMTP relay for SaaS notification email. Authenticate once, send user alerts and lifecycle mail reliably.When a dedicated IP helpsNeed sending isolation? Dedicated IP options are available on supported Layer 9 SMTP plans.SMTP AUTH in plain EnglishHow SMTP AUTH works with Layer 9: username, password, TLS, and mail.l9s.io endpoints.mail.l9s.io — your SMTP endpointUse mail.l9s.io as your SMTP host for Layer 9 relay. Ports 587 and 465 with TLS and SMTP AUTH.Bulk and transactional are not the sameKnow the difference between bulk marketing and transactional email. Layer 9 SMTP is built for transactional streams.Simple SMTP pricingLayer 9 SMTP pricing from £5/mo. Transparent tiers for volume, domains, API/webhooks and enterprise needs.PHPMailer → Layer 9 SMTPConfigure PHPMailer to send via Layer 9 SMTP with TLS and SMTP AUTH on mail.l9s.io.Django email via Layer 9Configure Django EMAIL_HOST for Layer 9 SMTP. Send Django emails through mail.l9s.io securely.Cart emails need authenticated SMTPDeliver abandoned cart and order emails reliably with Layer 9 SMTP for WooCommerce stores.People mail vs app mailGoogle Workspace is for people mailboxes. Layer 9 SMTP is for application transactional email — use both correctly.