high severitySendGrid Email API (Dynamic Templates)

Emails are automatically dropped with 'Invalid Template' reason in activity feed, despite API returning 202 success and recipients not suppressed. No email delivery occurs, leading to silent failures in production.

Root cause

SendGrid validation rejects requests using non-existent or inactive template versions, marking emails as 'Invalid Template' and dropping them silently (API returns 202 Accepted, but no delivery occurs).

SendGriddynamic templatesInvalid Templatedropped emailstemplate IDactive version

Citations

Emails are automatically dropped with 'Invalid Template' reason in activity feed, despite API returning 202 success and recipients not suppressed. No email delivery occurs, leading to silent failures in production. — high Severity | Agentifact Bug Library