Category: Blog

DKIM (DomainKeys Identified Mail) is an email authentication standard defined in RFC 6376 that lets a receiving mail server verify two things: the message was authorized by the owner of a specific domain, and the message content was not altered in transit. It does this through a public/private key pair: the sender signs outgoing mail…

Use port 587 with STARTTLS for virtually all application email submission. It is the standard submission port defined in RFC 6409 and requires authentication before accepting mail. If your network or firewall blocks 587, try port 465 (implicit TLS, re-standardized in RFC 8314) or port 2525 (a non-official but widely supported fallback). Port 25 is…

A complete reference guide to SPF record syntax: version tag, mechanisms (a, mx, ip4, ip6, include, exists), qualifiers (+ – ~ ?), the -all vs ~all choice, the 10-lookup limit, and annotated real-world examples.

The best MailerLite alternative depends on where the fit breaks down for your team. For transactional email, Postmark or MailerSend are the clearest upgrades. For SaaS lifecycle automation with event triggers, Loops or Customer.io handle product-driven workflows that MailerLite was not designed for. For developer teams wanting a clean sending API, Resend or Mailgun fit…

Spam traps are monitoring addresses used by mailbox providers and blocklist operators to catch senders with poor list hygiene. Learn the three types, how you end up hitting them, and the practical steps that keep your list clean.

Learn how to structure an HTML email with nested tables, modular sections, and a ~600px wrapper so it renders consistently in Gmail, Apple Mail, and Outlook.

An SMTP relay is a third-party service that accepts your outbound mail and handles the actual server-to-server delivery for you, including reputation management, bounce processing, and suppression lists. Here is how it works and when you need one.

A code-first tutorial covering table-based layouts, the fluid/hybrid approach, media queries, Outlook MSO ghost table caveats, and a minimal working responsive HTML snippet.

BIMI (Brand Indicators for Message Identification) is a DNS-based standard that lets you display your company logo directly in the inbox, next to your sender name. Gmail, Yahoo Mail, and Apple Mail show a verified logo when your domain passes strict authentication checks and, in most cases, holds a cryptographic certificate proving logo ownership. The…

Double opt-in requires new subscribers to confirm their email address before joining your list. Here is how it works, when to use it, and what GDPR says.

A practical guide to re-engagement and win-back email campaigns for SaaS: when to trigger, campaign structure, what to send, and when to suppress.

A merge tag is a placeholder in your email template that your ESP replaces with recipient-specific data at the moment each message is sent. Write {{ customer.first_name }} once in your template, and every subscriber gets their actual name in that spot. The placeholder is gone by the time the email hits an inbox; what…