AgentMail, a San Francisco-based startup, has raised $6 million in a seed funding round to develop an email infrastructure specifically designed for artificial intelligence agents. The funding round was led by General Catalyst, with participation from Y Combinator, Phosphor Capital, and several angel investors including Paul Graham, HubSpot CTO Dharmesh Shah, Supabase CEO Paul Copplestone, and Ramp CTO Karim Atiyeh.
The company is developing an API-driven email platform that allows AI agents to have their own email inboxes. Through this system, developers can assign inboxes to AI systems, enabling them to send and receive emails, participate in two-way conversations, and organize messages using features such as parsing, threading, labeling, searching, and replying.
AgentMail’s platform is designed to function similarly to traditional email services such as Gmail or Outlook, but it is optimized for AI systems rather than human users. Instead of interacting through a graphical interface, AI agents can manage inboxes and communications using API calls, allowing them to automate tasks like responding to emails, organizing conversations, and integrating with other digital services.
Alongside the funding announcement, the startup also introduced an onboarding API that allows AI agents to automatically create and manage their own email accounts. Developers can configure inboxes, permissions, allowlists, and API keys to control how AI agents access and use the platform.
The founders believe that as AI agents become more widely used across the internet, they will require digital identities and communication channels similar to those used by humans. Providing AI agents with email addresses allows them to interact with existing online services that rely on email-based authentication and communication.
Since launching through Y Combinator’s Summer 2025 batch, AgentMail has attracted tens of thousands of human users along with hundreds of thousands of AI agent users. The platform is also being used by more than 500 businesses.
To prevent misuse, the company has implemented safeguards within the system. Newly created agent inboxes are initially restricted to sending a maximum of 10 emails per day unless verified by a human user. The platform also monitors activity levels, tracks bounce rates, and scans new accounts for sensitive keywords to reduce the risk of spam or abuse.
As AI agents continue to take on tasks such as scheduling meetings, running marketing campaigns, and managing workflows, platforms like AgentMail aim to provide the infrastructure needed for automated digital communication at scale.
