docs: Added Mailchimp MCP Server to README

Author: rishabhraj36

README.md

@@ -461,6 +461,7 @@ A growing set of community-developed and maintained servers demonstrates various
 - **[lucene-mcp-server](https://github.com/VivekKumarNeu/MCP-Lucene-Server)** - spring boot server using Lucene for fast document search and management.
 - **[mac-messages-mcp](https://github.com/carterlasalle/mac_messages_mcp)** - An MCP server that securely interfaces with your iMessage database via the Model Context Protocol (MCP), allowing LLMs to query and analyze iMessage conversations. It includes robust phone number validation, attachment processing, contact management, group chat handling, and full support for sending and receiving messages.
 - **[Maestro MCP](https://github.com/maestro-org/maestro-mcp)** - An MCP server for interacting with Bitcoin via the Maestro RPC API.
+- **[Mailchimp](https://github.com/universal-mcp/mailchimp)** - Mailchimp MCP server from **[agentr](https://agentr.dev/)** that provides support for email marketing via Mailchimp.
 - **[MalwareBazaar_MCP](https://github.com/mytechnotalent/MalwareBazaar_MCP)** (by Kevin Thomas) - An AI-driven MCP server that autonomously interfaces with MalwareBazaar, delivering real-time threat intel and sample metadata for authorized cybersecurity research workflows.
 - **[MariaDB](https://github.com/abel9851/mcp-server-mariadb)** - MariaDB database integration with configurable access controls in Python.
 - **[Markdown2doc](https://github.com/Klavis-AI/klavis/tree/main/mcp_servers/pandoc)** - Convert between various file formats using Pandoc