Enterprise Email Agents with Semantic Kernel

import requests
import semantic_kernel as sk
from semantic_kernel.functions.kernel_function_decorator import kernel_function

MULTIMAIL_API = "https://api.multimail.dev/v1"
HEADERS = {"Authorization": "Bearer mm_live_your_api_key"}

class MultiMailPlugin:
    @kernel_function(description="Send an email. In gated_send mode, queues for approval.")
    def send_email(self, to: str, subject: str, body: str, mailbox_id: str) -> str:
        resp = requests.post(f"{MULTIMAIL_API}/send", headers=HEADERS, json={
            "mailbox_id": mailbox_id, "to": to,
            "subject": subject, "body": body
        })
        return str(resp.json())

    @kernel_function(description="Check inbox for recent messages.")
    def check_inbox(self, mailbox_id: str, limit: int = 10) -> str:
        resp = requests.get(
            f"{MULTIMAIL_API}/mailboxes/{mailbox_id}/inbox",
            headers=HEADERS, params={"limit": limit}
        )
        return str(resp.json())

    @kernel_function(description="Reply to an email by message ID.")
    def reply_email(self, message_id: str, body: str) -> str:
        resp = requests.post(f"{MULTIMAIL_API}/reply", headers=HEADERS, json={
            "message_id": message_id, "body": body
        })
        return str(resp.json())

    @kernel_function(description="List all mailboxes for the account.")
    def list_mailboxes(self) -> str:
        resp = requests.get(f"{MULTIMAIL_API}/mailboxes", headers=HEADERS)
        return str(resp.json())

from semantic_kernel import Kernel
from semantic_kernel.connectors.ai.open_ai import AzureChatCompletion
from semantic_kernel.connectors.ai.open_ai import OpenAIChatCompletion
from semantic_kernel.connectors.ai.function_choice_behavior import FunctionChoiceBehavior
from semantic_kernel.contents.chat_history import ChatHistory

kernel = Kernel()

"cm"># Add LLM service
kernel.add_service(OpenAIChatCompletion(
    service_id="chat", ai_model_id="gpt-4o"
))

"cm"># Register MultiMail plugin
kernel.add_plugin(MultiMailPlugin(), plugin_name="multimail")

"cm"># Configure automatic function calling
settings = kernel.get_prompt_execution_settings_from_service_id("chat")
settings.function_choice_behavior = FunctionChoiceBehavior.Auto()

chat_history = ChatHistory()
chat_history.add_system_message(
    "You are an email assistant using MultiMail. The mailbox operates "
    "in gated_send mode — sent emails require human approval before delivery."
)
chat_history.add_user_message("Check my inbox and summarize any unread messages")

result = await kernel.invoke_prompt(
    "{{$chat_history}}",
    chat_history=chat_history,
    settings=settings
)
print(result)

using Microsoft.SemanticKernel;
using System.ComponentModel;
using System.Net.Http.Json;

public class MultiMailPlugin
{
    private readonly HttpClient _client;
    private const string BaseUrl = "https://api.multimail.dev/v1";

    public MultiMailPlugin(string apiKey)
    {
        _client = new HttpClient();
        _client.DefaultRequestHeaders.Add("Authorization", $"Bearer {apiKey}");
    }

    [KernelFunction, Description("Send an email. In gated_send mode, queues for approval.")]
    public async Task<string> SendEmail(string to, string subject, string body, string mailboxId)
    {
        var response = await _client.PostAsJsonAsync($"{BaseUrl}/send", new
        {
            mailbox_id = mailboxId, to, subject, body
        });
        return await response.Content.ReadAsStringAsync();
    }

    [KernelFunction, Description("Check inbox for recent messages.")]
    public async Task<string> CheckInbox(string mailboxId, int limit = 10)
    {
        var response = await _client.GetAsync($"{BaseUrl}/mailboxes/{mailboxId}/inbox?limit={limit}");
        return await response.Content.ReadAsStringAsync();
    }

    [KernelFunction, Description("Reply to an email by message ID.")]
    public async Task<string> ReplyEmail(string messageId, string body)
    {
        var response = await _client.PostAsJsonAsync($"{BaseUrl}/reply", new
        {
            message_id = messageId, body
        });
        return await response.Content.ReadAsStringAsync();
    }
}