Glossary

WordPress email glossary

Short, factual definitions of the most important terms around WordPress email delivery, FreddyMail and deliverability.

SMTP (Simple Mail Transfer Protocol)

Protocol for sending email between servers. Without configuration, WordPress uses the PHP mail() function, which is often unreliable. With SMTP, FreddyMail hands emails over to a verified mail host (your own provider, hosting SMTP or a delivery service).

SPF (Sender Policy Framework)

DNS TXT record listing which servers are allowed to send mail for your domain. Receiving servers reject mail from servers not in your SPF. Without SPF, WordPress mails often land in spam.

DKIM (DomainKeys Identified Mail)

DNS record with a public key. The sending server signs each mail with the private counterpart; receivers verify the signature. Together with SPF, DKIM is critical for deliverability.

DMARC (Domain-based Message Authentication, Reporting and Conformance)

Policy record that tells receivers what to do with mail that fails SPF or DKIM (deliver, quarantine, reject). Gmail and Yahoo now require DMARC for bulk senders.

Bounce

A message returned by the receiving server. Hard bounce: the address does not exist. Soft bounce: temporary issue (mailbox full, server briefly unreachable). High bounce rates damage sender reputation.

Transactional email

A single email triggered by a user action: password reset, account verification, WooCommerce order confirmation, shipping notification. Distinct from newsletters that are scheduled to lists.

wp_mail()

Core WordPress function that plugins and core use to generate outgoing mail. FreddyMail hooks into wp_mail, replaces the delivery path and logs every message.

Email type

In FreddyMail, the classification of a mail by reason: password reset, new user, WooCommerce order confirmation, refund, custom plugin mail. Each type can get its own template.

HTML email

Email with formatting using a constrained subset of HTML/CSS that works across most mail clients. Layouts rely on tables and inline styles, since clients such as Outlook do not support modern CSS.

Delivery log

List of all outgoing WordPress mail with timestamp, recipient, type, status and provider response. Essential for diagnosing missing order confirmations or password reset emails.

API provider

Providers such as SendGrid, Mailgun, Brevo or Amazon SES that accept mail via HTTPS API rather than SMTP. Benefits: clear error responses, better scaling and more detailed status info. FreddyMail bundles these four API providers in the Pro plans.

Rate limit

Maximum number of mails per time window a provider accepts. Usually sufficient for transactional mail; bulk sending through transactional endpoints leads to throttling or account suspension.

Verified sender domain

A domain registered and verified via DNS at your provider. Only after verification can you use noreply@yourdomain.tld as sender without rejection.

Freemius

Third-party platform handling purchase, license, invoices, subscription management and refunds for FreddyMail Pro.