Category: Blog

Postmark prices by monthly email volume, not prepaid credits: four plans from free to $18/mo, overage rates that drop as you grow, and a shared quota across transactional and broadcast streams. Here is the full structure with a worked cost example.

Email bounce rate measures the percentage of sent messages that failed to deliver. Learn the formula, what the thresholds mean for your sender reputation, and the concrete steps that keep your bounce rate below 2%.

Postmark is the top pick for inbox placement on critical transactional sends. Amazon SES wins on raw cost at volume. Brevo and Loops handle the transactional-plus-lifecycle combination. Mailtrap adds a testing sandbox alongside production sending. This guide covers seven verified alternatives with real pricing and a use-case decision matrix.

A secure password reset email combines a single-use, time-limited token with a clear one-button message that matches your product identity. This guide covers the full flow for developers and the email mechanics for product teams, with a ready-to-adapt template.

The email preheader (preview text) is the short line shown after your subject in the inbox. Learn what it is, how to write one that lifts open rates, how to implement the hidden preheader span in HTML, and see before/after examples.

The List-Unsubscribe header is an email header field that lets mailbox providers render a native “Unsubscribe” button at the top of a message, separate from any unsubscribe link in the body. When paired with the List-Unsubscribe-Post header defined in RFC 8058, that button triggers a true one-click unsubscribe: the mail client sends an HTTP POST…

Email warmup is the practice of gradually increasing sending volume from a new domain or IP address so that Gmail, Outlook, Yahoo, and other mailbox providers build a positive reputation for you before you send at full scale. The method: start with tens or low hundreds of emails per day to your most engaged recipients,…

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.