Regression: Fix duplicate email messages in multiple instances

app/models/server/models/EmailMessageHistory.js

@@ -0,0 +1,10 @@
+import { Base } from './_Base';
+
+export class EmailMessageHistory extends Base {
+	constructor() {
+		super('email_message_history');
+		this.tryEnsureIndex({ createdAt: 1 }, { expireAfterSeconds: 60 * 60 * 24 });
+	}
+}
+
+export default new EmailMessageHistory();

app/models/server/raw/EmailMessageHistory.ts

@@ -0,0 +1,13 @@
+/* eslint-disable @typescript-eslint/explicit-function-return-type */
+import { BaseRaw } from './BaseRaw';
+import { IEmailMessageHistory } from '../../../../definition/IEmailMessageHistory';
+
+export class EmailMessageHistoryRaw extends BaseRaw<IEmailMessageHistory> {
+	insertOne({ _id, email }: IEmailMessageHistory) {
+		return this.col.insertOne({
+			_id,
+			email,
+			createdAt: new Date(),
+		});
+	}
+}

app/models/server/raw/index.ts

@@ -65,6 +65,8 @@ import OmnichannelQueueModel from '../models/OmnichannelQueue';
 import { OmnichannelQueueRaw } from './OmnichannelQueue';
 import EmailInboxModel from '../models/EmailInbox';
 import { EmailInboxRaw } from './EmailInbox';
+import EmailMessageHistoryModel from '../models/EmailMessageHistory';
+import { EmailMessageHistoryRaw } from './EmailMessageHistory';
 import { api } from '../../../../server/sdk/api';
 import { initWatchers } from '../../../../server/modules/watchers/watchers.module';
 
@@ -103,6 +105,7 @@ export const IntegrationHistory = new IntegrationHistoryRaw(IntegrationHistoryMo
 export const Sessions = new SessionsRaw(SessionsModel.model.rawCollection(), trashCollection);
 export const OmnichannelQueue = new OmnichannelQueueRaw(OmnichannelQueueModel.model.rawCollection(), trashCollection);
 export const EmailInbox = new EmailInboxRaw(EmailInboxModel.model.rawCollection(), trashCollection);
+export const EmailMessageHistory = new EmailMessageHistoryRaw(EmailMessageHistoryModel.model.rawCollection(), trashCollection);
 
 const map = {
 	[Messages.col.collectionName]: MessagesModel,

definition/IEmailMessageHistory.ts

@@ -0,0 +1,5 @@
+export interface IEmailMessageHistory {
+	_id: string;
+	email: string;
+	createdAt?: Date;
+}

server/features/EmailInbox/EmailInbox.ts

@@ -2,7 +2,7 @@ import { Meteor } from 'meteor/meteor';
 import nodemailer from 'nodemailer';
 import Mail from 'nodemailer/lib/mailer';
 
-import { EmailInbox } from '../../../app/models/server/raw';
+import { EmailInbox, EmailMessageHistory } from '../../../app/models/server/raw';
 import { IMAPInterceptor } from '../../email/IMAPInterceptor';
 import { IEmailInbox } from '../../../definition/IEmailInbox';
 import { onEmailReceived } from './EmailInbox_Incoming';
@@ -46,7 +46,18 @@ export async function configureEmailInboxes(): Promise<void> {
 			markSeen: true,
 		});
 
-		imap.on('email', Meteor.bindEnvironment((email) => onEmailReceived(email, emailInboxRecord.email, emailInboxRecord.department)));
+		imap.on('email', Meteor.bindEnvironment(async (email) => {
+			if (!email.messageId) {
+				return;
+			}
+
+			try {
+				await EmailMessageHistory.insertOne({ _id: email.messageId, email: emailInboxRecord.email });
+				onEmailReceived(email, emailInboxRecord.email, emailInboxRecord.department);
+			} catch (e) {
+				// In case the email message history has been received by other instance..
+			}
+		}));
 
 		imap.start();