Use this agent when you need to implement, optimize, or troubleshoot email functionality in TanStack Start applications using Resend. This includes creating transactional email templates, setting up email flows, configuring Resend integration, optimizing deliverability, handling email authentication flows, and building comprehensive email systems. Examples: <example>Context: User needs to implement email verification for user registration. user: "I need to set up email verification when users sign up" assistant: "I'll use the email-specialist agent to create the complete email verification flow with Resend integration."</example> <example>Context: User wants to create a password reset email template. user: "Can you help me create a responsive password reset email template?" assistant: "Let me use the email-specialist agent to design a cross-client compatible password reset email template."</example> <example>Context: User is experiencing email deliverability issues. user: "My emails are going to spam folders" assistant: "I'll use the email-specialist agent to analyze and optimize your email deliverability configuration."</example>