SendGrid · api · fg-0416

SendGrid ignores the subject you pass when sending with a dynamic template

Email arrives with the template's subject, not the one in the request

Verified 2026-10-15 · Confirmed by 0 builders · Trust 50/100

Cause

A dynamic template version that defines a subject overrides any subject set at message or personalization level. To vary it per send, the template subject must itself be a Handlebars expression fed from dynamic_template_data.

Fix

Set the template version subject to {{{subject}}} and pass subject inside dynamic_template_data.

Apply

{ templateId: 'd-xxxxxxxx', dynamicTemplateData: { subject: 'Your order shipped', name: 'Ana' } }  // template subject field: {{{subject}}}

Affects: SendGrid v3 Mail Send with dynamic templates (d- ids), as of 2026-10

Sources

• https://www.twilio.com/docs/sendgrid/api-reference/mail-send/mail-send
• https://github.com/sendgrid/sendgrid-nodejs/issues/843

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