Guías de autenticación de correo electrónico
Guías prácticas y directas sobre SPF, DKIM y DMARC. Corrija lo que está mal y mantenga su correo fuera del spam.
Email Compliance: CAN-SPAM, GDPR and CASL Basics
A plain-English guide to the three laws that govern commercial email: CAN-SPAM in the US, GDPR in the EU, and CASL in Canada, covering consent, identification, unsubscribe, penalties, and how compliance overlaps with deliverability.
Dedicated vs Shared IP for Sending Email
A practical guide to choosing between a dedicated and a shared sending IP, weighing volume, reputation control, warmup burden, and cost, with a clear decision path.
Hard Bounce vs Soft Bounce Explained
A hard bounce is a permanent delivery failure that must be suppressed immediately; a soft bounce is temporary and worth retrying. This guide covers example SMTP codes, causes, bounce-rate thresholds, and the reputation cost of poor list hygiene.
What Is Greylisting and Why Email Gets Delayed
Greylisting temporarily defers mail from unfamiliar senders with a 4xx SMTP response so spam bots give up while real servers retry. Learn how the triplet works, why legitimate mail is only delayed, and what senders and admins should do.
What Is Microsoft SNDS and How to Read It
Microsoft SNDS is a free tool that shows how Outlook.com rates your sending IPs. Learn to read its data columns, enroll in SNDS and JMRP, and fix Outlook and Hotmail delivery.
What Is a Spam Trap and How to Avoid Them
Spam traps are dead or fake email addresses that flag senders with poor list hygiene. Learn the three types, how they get onto your list, the reputation damage they cause, and how to prevent hits.
What Is Spamhaus and How to Get Delisted
A practical guide to Spamhaus and its main blocklists (SBL, XBL, PBL, DBL, CSS), how listings happen, and how to check for and request removal.
What Is Sender Reputation and How to Improve It
Sender reputation is the trust score mailbox providers assign to your sending domain and IP based on complaints, bounces, spam-trap hits, engagement, and authentication. This guide explains what providers score, how to read it in Postmaster Tools and SNDS, and a practical plan to improve it.
How to Get Off an Email Blacklist (Delisting Guide)
A step-by-step delisting guide: identify which blacklist listed you, fix the root cause, submit the right removal request, and prevent re-listing. Covers Spamhaus, Barracuda, SpamCop, and the SORBS shutdown.
SMTP Error Codes Explained: 4xx and 5xx Bounces
A reference guide to SMTP reply codes and RFC 3463 enhanced status codes, covering the 2xx, 4xx, and 5xx classes, common bounces (421, 450, 451, 550, 552, 554), and how to act on each.
What Is the Return-Path (Envelope Sender)?
The Return-Path (envelope sender) is the hidden address SPF actually checks and where bounces are delivered. Learn how it differs from the visible From, why it controls SPF alignment for DMARC, and how a custom bounce domain fixes ESP traffic.
Email Deliverability Best Practices Checklist
A practical, checklist-driven guide to the seven pillars of email deliverability: authentication, infrastructure, warm-up, list hygiene, engagement, complaint and bounce thresholds, and monitoring.