/**
* Forward email functionality
*/
import { ensureAuthenticated } from "../auth";
import {
canSendFrom,
formatAllowedMailboxes,
} from "../config/mailbox-permissions";
import { callGraphAPI } from "../utils/graph-api";
/**
* MCP response content item
*/
interface MCPContentItem {
type: "text";
text: string;
}
/**
* MCP response structure
*/
interface MCPResponse {
content: MCPContentItem[];
isError?: boolean;
}
/**
* Arguments for forward email handler
*/
interface ForwardEmailArgs {
mailbox?: string;
id?: string;
toRecipients?: string;
comment?: string;
}
/**
* Email recipient structure for Graph API
*/
interface GraphRecipient {
emailAddress: {
address: string;
};
}
/**
* Forward email handler
*
* Forwards an email to the specified recipients with an optional comment.
*
* @param args - Tool arguments
* @returns MCP response
*/
export async function handleForwardEmail(
args: ForwardEmailArgs,
): Promise<MCPResponse> {
const mailbox = args.mailbox;
if (!mailbox) {
return {
content: [{ type: "text", text: "Mailbox address is required." }],
isError: true,
};
}
const emailId = args.id;
const toRecipientsStr = args.toRecipients;
const comment = args.comment ?? "";
if (!emailId) {
return {
content: [
{
type: "text",
text: "Email ID is required.",
},
],
isError: true,
};
}
if (!toRecipientsStr) {
return {
content: [
{
type: "text",
text: "Recipients (toRecipients) are required for forwarding.",
},
],
isError: true,
};
}
// Check if the mailbox has permission to send
if (!canSendFrom(mailbox)) {
return {
content: [
{
type: "text",
text: `Sending is not allowed from ${mailbox}. Allowed: ${formatAllowedMailboxes()}`,
},
],
isError: true,
};
}
try {
const accessToken = await ensureAuthenticated();
// Parse comma-separated recipients
const toRecipients: GraphRecipient[] = toRecipientsStr
.split(",")
.map((email) => ({
emailAddress: {
address: email.trim(),
},
}));
const requestBody = {
comment,
toRecipients,
};
// graph-api.ts handles path segment encoding — do NOT pre-encode emailId
const endpoint = `users/${mailbox}/messages/${emailId}/forward`;
try {
await callGraphAPI(accessToken, "POST", endpoint, requestBody);
const recipientList = toRecipients
.map((r) => r.emailAddress.address)
.join(", ");
return {
content: [
{
type: "text",
text: `Email forwarded successfully to: ${recipientList}`,
},
],
};
} catch (error) {
const errorMessage =
error instanceof Error ? error.message : String(error);
if (errorMessage.includes("doesn't belong to the targeted mailbox")) {
return {
content: [
{
type: "text",
text: "The email ID seems invalid or doesn't belong to your mailbox. Please try with a different email ID.",
},
],
isError: true,
};
}
if (errorMessage.includes("UNAUTHORIZED")) {
return {
content: [
{
type: "text",
text: "Authentication failed. Please re-authenticate and try again.",
},
],
isError: true,
};
}
return {
content: [
{
type: "text",
text: `Failed to forward email: ${errorMessage}`,
},
],
isError: true,
};
}
} catch (error) {
const errorMessage = error instanceof Error ? error.message : String(error);
if (errorMessage === "Authentication required") {
return {
content: [
{
type: "text",
text: "Authentication required. Please use the 'authenticate' tool first.",
},
],
isError: true,
};
}
return {
content: [
{
type: "text",
text: `Error accessing email: ${errorMessage}`,
},
],
isError: true,
};
}
}
export default handleForwardEmail;
