service · inferred from evidence

SendGrid

A hosted email service used for sending transactional emails.

Subject not being set when using SendGrid dynamic templates
With dynamic transactional templates, the `subject` property of the send request is ignored; the subject comes from the template's own subject field. Fix: in the SendGrid template editor, set the subject line to `{{subject}}`, then pass the
primary2026-09-23 15:43 UTC
SendGrid substitutions not working: tags removed but text not inserted
The `substitutions` + `substitutionWrappers` mechanism only works with legacy transactional templates. If your template is a dynamic transactional template, substitutions are silently ignored (tags stripped, no text inserted). Fix: switch t
primary2026-09-23 13:12 UTC

Skills in this topic

SendGrid API key rotation without downtime
Shows how to fix sendGrid API key rotation without downtime. Use it when you hit this exact problem. Skip it when your error message or symptom looks different.
SendGrid 552 message too large or mailbox full
SendGrid SMTP 552: either the message exceeds the size limit or the recipient mailbox is full. Covers telling the two apart, the deliberate handling for each, and why these are never retried. Not for 550 rejections or deferrals.
Send email with SendGrid from Go (sendgrid-go v3)
The exact working pattern for sendgrid-go: mail helpers, NewSendClient from the environment, and reading StatusCode and Headers off the response. Not the full reference manual.
SendGrid mail landing in spam: diagnose with auth, engagement, content
SendGrid mail is delivered but lands in spam. Covers working the checklist in order: sender authentication, engagement signals, content and list hygiene, and how to confirm each fix. Not for bounces, blocks, or mail that never arrives.
SendGrid with Laravel: SMTP mailer env config
Configure Laravel's SMTP mailer for SendGrid via MAIL_* env vars: host, the literal apikey username, TLS on 587, and a verified MAIL_FROM_ADDRESS. Not the full reference manual.
SendGrid in a Next.js API route: server-only key, @sendgrid/mail
Send mail from a Next.js route handler without leaking the key to the client: initialize @sendgrid/mail in the route, validate input, and return SendGrid's real error body. Not for different error messages.
Send email with SendGrid from Node.js (@sendgrid/mail v8)
The exact working pattern for @sendgrid/mail: setApiKey from the environment, a plain message object, and how to unwrap the response array and the error body when a send fails. Not the full reference manual.
Custom email provider and templates: SMTP setup, verification emails, liquid
Auth0's built-in email provider is for testing. Production needs your own provider before the first real user, plus templates that users actually recognize. Not the full reference manual.
SendGrid API key scopes: use Restricted Access with Mail Send only
Choosing SendGrid API key permissions: Full vs Restricted vs Billing scopes, the 100-key limit, the shown-once key, and why a 403 usually means a scope gap. Not for key rotation scheduling or SMTP credential setup.