Email

1 Introduction

The Email connector allows you to send and receive emails on your own email server. It includes features such as sending emails using a template, or sending signed and encrypted emails.

1.1 Features

The Email connector includes the following features:

• Configuration of multiple email accounts
  • Supports basic authentication and creating an account with OAuth 2.0 (via authorization code flow or client credentials flow) to configure Microsoft Entra ID (formerly known as Azure Active Directory) accounts
  • Supports shared mailboxes using basic and OAuth 2.0 authentication
• Digital signatures and encryption
• Email templates
• Sending and receiving emails with OAuth 2.0 Auth code grant or client credentials flow.

The Email connector supports the following protocols:

• POP3 and POP3S
• IMAP and IMAPS
• SMTP

1.2 Prerequisites

Before you use the Email connector in your app, do the following:

• Download and configure the latest version of the Mx Model Reflection module. If you have the module already, ensure that it is up to date.
• Download and configure the latest version of the Encryption module. If you have the module already, ensure that it is up to date.
• Remove any existing email modules (such as IMAP/POP3 and Email Module with Templates).
• Remove any orphaned JAR files (including javax.mail-1.6.2.jar, activation-1.1.jar, and commons-email.jar) from any old email modules in the userlib subdirectory.
• Clean the deployment directory.

1.2.1 Migrating from Another Module

If you are migrating to the Email connector from another email module, consider testing your settings in a new app first.

It is recommended to use the community-supported Email Connector Migration Utility module to migrate data from the Email Module with Templates service.

1.3 Included Widgets

The following widgets are bundled in the module:

• HTML Element
• Rich Text

2 Setup in Studio Pro

After you install the Email connector, configure the following in Studio Pro:

1. Provide a value for the EncryptionKey constant provided by the Encryption module, if you did not complete this step in Prerequisites.
2. Launch the user interface by using the ACT_EmailAccount_LaunchEmailConnectorOverview microflow in the USEME > Microflows folder.

2.1 Module Security and Roles

The module comes with a default EmailConnectorAdmin module role. Access rights for this role have been set with wide use cases in mind. Confirm that the access rights fit your use case and security requirements before linking the module role to user roles in App Security.

3 Email Account Configuration

Once you run your Studio Pro app, you can start configuring your email accounts in the Email connector UI.

3.1 Adding Email Account

When you run your app to use the Email connector module for the first time (and if no earlier data is present), you will see a welcome screen with an account setup wizard. Click Get Started and follow the steps to add email accounts. The wizard takes you through three steps to configure either your primary email account or a shared mailbox:

1. Select the authentication method that you want to use. You can choose either Use Basic Credentials or Use Microsoft Entra ID (OAuth 2.0).
2. Select if you want to configure a primary mailbox or a shared mailbox.
3. Select your desired protocols for sending and receiving emails.

You can add and configure primary and shared mailboxes in the Email Connector using basic authentication or OAuth 2.0 for Microsoft Entra ID accounts. For OAuth authentication, you can use the authorization code flow or the client credentials flow.

For details on how to configure OAuth 2.0 accounts, see Creating an Account Using Microsoft Azure OAuth 2.0. The account configuration wizard supports automatic and manual configurations for sending and receiving emails.

3.1.1 Automatic Configuration

Based on the entered email address domain, the module will try to fetch configuration details for sending and receiving email. This auto-discovery of configuration works for well-known email domains (including Gmail, Outlook, Yahoo, and Microsoft). If the module fails to detect the email settings automatically, it will prompt you to enter them manually to add the email account.

In Studio Pro, it is also possible to use the GetAutoConfig Java action to get all supported email configurations for the provided user name. This action returns results as Email_Connector.EmailProvider. Process the Email_Connector.EmailProvider records to get the desired configuration and create the Email_Connector.EmailAccount.

3.1.2 Manual Configuration

To manually configure the account for sending and receiving emails, enter the protocol, server host, and server port. Refer to the email server documentation to get this information.

3.2 Additional Account Settings

You can choose to adjust the following account settings:

• Subscribe to incoming emails – By default, this is turned off. Turn it on if you want to get notifications about new incoming emails. For modeling, use the SubscribeToIncomingEmail Java action. Note that this setting is only supported for IMAP protocols, and some servers may not support it at all. For more information, see the Subscribing to Incoming Email section below.
• Sanitize email to prevent XSS attacks – By default, this is turned off, but it is strongly recommended to turn it on. Turn it on if you want the connector to remove malicious scripts to prevent XSS attacks. To learn more about this option, see Sanitize Untrusted HTML (To Prevent XSS).
• Replicate everything in ‘Inbox’ folder – By default, this is turned off. When it is off, the connector will fetch the number of emails mentioned in the Number of emails to retrieve from server field, based on the selected Fetch strategy. Turn this setting on if you want the connector to fetch all the emails from the inbox (or another folder that you specify), in the batch size specified in the Email batch size field. The emails will be ordered from oldest to newest.
• Connection Timeout (milliseconds) – By default, this is set to 20000. If you want to adjust the connection timeout duration for sending and receiving emails, you can change this value in the account settings or the EmailAccount object.

4 Usage

Once you have set up an account, you can use it in microflow activities to send and receive emails. The information in the following sections includes usage instructions for Studio Pro, as well as for when you run the connector in your app.

4.1 Sending Email

When the module is running, click New Email to compose and send new emails.

When modeling your app in Studio Pro, use the SendEmail Java action to send emails. The input parameters are as follows:

• EmailAccount – email account consisting of the outgoing email configuration
• EmailMessage – the EmailMessage object to be sent

The return type is a Boolean value. This Java action uses the provided details to connect to the email server and send an email. It returns True if successful and displays the error object and cause if it fails.

When sending an email, the To and Content fields are mandatory. In To, CC, and BCC, you can optionally specify multiple email addresses, each separated by a semicolon (;).

4.2 Receiving Email

Click Fetch Emails to receive emails. Emails are fetched in the background and processed by the server, as configured in the email account.

When modeling your app in Studio Pro, use the RetrieveEmailMessages Java action. Once this Java action is called in the background, emails are fetched over multiple Java threads and returned asynchronously. Email fetching continues until the conditions defined in the email account settings are met. For example, you could set the app to fetch the latest 1,000 emails. For more information, see Additional Account Settings.

The input parameters for receiving email are the following:

• EmailAccount – This is an email account consisting of the incoming email configuration.

• onEmailFetchMicroflow – This is a microflow that is triggered when List of EmailMessage is fetched from the email server, as per the batch size specified in the email account settings. You can process the list according to your needs.

  If duplicating the onEmailFetchMicroflow microflow, do not change the input parameter name or data type. To prevent errors, make sure you have List of Email_Connector.EmailMessage as a parameter to this microflow.

• onFetchCompleteMicroflow – This is a microflow that is triggered when the fetch action is successfully completed.

• onFetchErrorMicroflow – This is a microflow that is triggered if there are errors while fetching from the email server.

4.3 Using Email Templates

You can create and use templates for a specific email account.

4.3.1 Creating an Email Template

You can create email templates in two ways:

• While running the app, click the Email Templates button and follow the wizard.
• While modeling the app in Studio Pro, use the SNIP_EmailTemplate_Overview snippet located in Private > Snippets. Use the snippet on a page and save it on a button click.

4.3.2 Creating an Email Message from a Template

When modeling your app in Studio Pro, use the CreateEmailFromTemplate Java action to create a draft message that you can preview and modify. Once your message is ready, you can send it with the SendEmail action.

The input parameters are the following:

• DataObject – This is an entity object from which you want to extract the placeholder tokens. If you want to retrieve from multiple objects, create a non-persistable entity.
• EmailTemplate – This is an email template from which an EmailMessage object is created and sent.
• Queued – When true, the email message is stored in the EmailMessage entity with its status as Queued. In this case, you can send it later using a scheduled event. You can use the microflow SE_SendQueuedEmails to create scheduled events. You can also create a task queue and run this microflow in that task queue to minimize system resource usage. Using a task queue, you can set the number of threads, node or cluster-wide scope, time intervals, and other parameters.

Refer to the sample microflow Sample_ACT_CreateEmailFromTemplateAndThenSend. This microflow demonstrates how to use the CreateEmailFromTemplate Java action and set attachments to EmailMessage in addition to attachments provided by EmailTemplate.

4.3.3 Sending an Email with a Template

When modeling your app in Studio Pro, use the SendEmailWithTemplate Java action to send an email from a template. The input parameters are the following:

• Data Object – This is an entity object from which you want to extract the placeholder tokens. If you want to retrieve from multiple objects, create a non-persistable entity.
• EmailAccount – This is an email account consisting of the outgoing email configuration.
• EmailTemplate – This is an email template from which an EmailMessage object is created and sent.
• Queued – When true, the email message is stored in the EmailMessage entity with its status as Queued. In this case, you can send it later using a scheduled event. You can use the SE_SendQueuedEmails microflow to create scheduled events. You can also create a task queue and run the microflow in that task queue to minimize system resource usage. Using a task queue, you can set the number of threads, node or cluster-wide scope, time intervals, and other parameters.

Refer to the sample microflow Sample_ACT_SendEmailWithTemplate. To use To, CC, or BCC during runtime, change the EmailTemplate object and set the desired values for the attributes, then pass the same EmailTemplate object as a parameter to the Java action.

4.4 Signed and Encrypted Emails

You can choose to configure a digital signature and email encryption when the module is running. Digital signatures help the receiver verify that you are the sender. Encryption scrambles the message and can only be deciphered with the correct key.

4.4.1 Digital Signing

Digitally signed emails support only PKCS#12 certificates.

4.4.2 Email Encryption

Encryption for emails using the Email connector includes the following:

• Support for LDAP servers for sending encrypted emails
• Two options for authentication methods: Simple and No (anonymous)
• Support for SSL/TLS and non-SSL connection types
• While encrypting email, the recipient’s public certificate will be searched for on the base DN

4.5 Subscribing to Incoming Email

When modeling your app in Studio Pro, call the SubscribeToIncomingEmail Java action to subscribe to incoming email from an account.

The input parameters are the following:

• EmailAccount – This is an email account consisting of the incoming email configuration.

• onNewEmailReceivedMicroflow – This is a microflow that is triggered when new email is received from the server. You can process the list of emails according to your needs.

  If duplicating the onNewEmailReceivedMicroflow microflow, do not change the input parameter name or data type. To prevent errors, make sure you have List of Email_Connector.EmailMessage as a parameter to this microflow.

• onSubscriptionStateChangedMicroflow – This is a microflow that is triggered when the subscription state is changed. The state can be any of the following values:

  • SUBSCRIPTIONFAILED
  • CONNECTIONTOSERVERLOST
  • CONNECTIONRETRYEXHAUSTED
  If duplicating the onSubscriptionStateChangedMicroflow microflow, do not change the input parameter names or data types. To prevent errors, the microflow must accept the string parameters State and Comment.

4.5.1 Enabling Subscription in Email Settings

For some use cases, like triggering actions when a new email is received, you need to enable the subscription to new emails in the email settings as well as in the subscription microflow documented in Subscribing to Incoming Email.

4.5.2 Additional Considerations

When subscribing to incoming email, keep the following additional considerations in mind:

• It is recommended to unsubscribe from any incoming email before subscribing to incoming email. This helps prevent the application from having duplicate subscriptions for a single email account. The complete subscription flow is shown in the SUB_EmailAccount_SubscribeForEmailNotification microflow.

• The subscription to new emails works only if the email account is configured with IMAP/S protocol and if the email server supports notifications. The subscription will end if the app is stopped. To subscribe again between app restarts, register the Sample_ASU_SubscribeForEmailNotification microflow in the After Startup option.

4.6 Unsubscribing from Incoming Email

When modeling your app in Studio Pro, use the UnsubscribeFromIncomingEmail Java action. When used with account parameters, the provided account will be unsubscribed from incoming email.

There is one input parameter:

• EmailAccount – email account consisting of the incoming email configuration

4.7 Configuring Azure OAuth 2.0

You can configure your account to authenticate with Microsoft Entra ID OAuth 2.0. Multiple OAuth 2.0 providers can be configured per app.

If no email accounts are configured, you can create a new OAuth configuration from the Add Email Account wizard by selecting Use Microsoft Entra ID. Otherwise, select OAuth Configurations to add, delete, and edit OAuth configurations, as described in the next section.

4.7.1 OAuth Provider Configuration Details

To configure an OAuth provider for the authentication code flow, provide the following details:

• Client ID – available on the Azure portal once you have registered your app
• Client Secret – available on the Azure portal once you have registered your app
• Callback Path – enter any string, and the callback URL will be autogenerated based on this string
• Callback URL – available on the Azure portal as the Redirect URI, which is the URL where the OAuth provider will redirect with the authorization code

To configure an OAuth provider for the client credentials grant flow, provide the following details, which are available on the Azure portal once you have registered your app:

• Client ID
• Client Secret
• Tenant ID

With Email Connector version 5.2.0 and newer, you can send emails using a client credentials flow.

4.7.2 Settings in the Microsoft Azure Portal (Authentication Code Flow)

To register your app on the Azure portal, follow Microsoft’s tutorial Register an app with Microsoft Entra ID. As mentioned above in OAuth Provider Configuration Details, make sure to set the Redirect URI as the Callback URL.

This connector contains functionality for sending and receiving emails, so during the OAuth process, the connector will ask for permissions for sending and receiving emails.

On the Azure portal, ensure you have the following permissions enabled under the API permissions tab on the sidebar:

4.7.3 Settings in the Microsoft Azure Portal (Client Credentials Flow)

To register your app in the Azure portal, follow Microsoft’s Register an app with Microsoft Entra ID.

This connector contains functionality for sending and receiving emails, so APIs related to Office 365 Exchange Online need to be given permission along with admin consent.

On the Azure portal, ensure you have the following permissions enabled under API permissions tab on the sidebar:

Admin status is given on the added API permissions. The tenant admin must register the Azure application’s service principal in Exchange via Exchange Online PowerShell, as described in Register service principals in Exchange.

4.8 Queuing Emails

Emails can be queued to be sent later. You can send the messages in the Queued folder at any time. If sending queued messages fails, the connector automatically tries resending it again until Max. send attempts is reached. After this limit is reached, any unsent messages are moved from the Queued tab to the Failed tab on the overview page.

5 Troubleshooting

5.1 Sending or Receiving Email

If you encounter any problems with sending or receiving emails, check the Error logs in the Account Settings and the logs in Studio Pro. If you have sent an email and it does not appear in your app, but there is nothing in the log file, then the error is not on the connector side.

5.1.1 Gmail Accounts

Gmail no longer supports basic authentication (user names and passwords), but you may still be able to set up an account in the Email connector by doing the following:

1. Read Less secure apps & your Google Account and turn off the Less secure app access setting in your Google account.
2. Set up an app password to sign in to the Email connector. For more information, see Sign in with app passwords.

5.2 Adding OAuth 2.0 Configuration to an App with Basic Authentication

If you already have an email account configured using basic authentication in your app, and you want to use OAuth 2.0 authentication without removing that email account, do the following:

1. On the overview page, click OAuth Configurations and add a new configuration. For more information, see OAuth Provider Configuration Details.
2. For the desired email account, set the isOAuthUsed attribute of the EmailAccount entity to True.
3. Associate the email account with your newly created OAuth provider.
4. Navigate to the overview page, click Manage Accounts, and select the account.
5. Go to the Server Settings tab in Account Settings and select Re-authenticate Access.

5.3 Deploying to On-Premises Cloud Environments

When deploying on premises running Microsoft Windows, you need to add a rule for a URL redirect. Add the following rule to the web.config file where the on-premises application is installed:

<rule name="mxecoh">
   <match url="^(mxecoh/)(.*)" />
   <action type="Rewrite" url="http://localhost:8080/{R:1}{R:2}" />
</rule>

For more information, see the Reverse Proxy Inbound Rules section of How to Deploy Mendix on Microsoft Windows.

5.4 Configuring Local Email Clients

Configuring local clients, such as Papercut, is supported. If you are using a tool like Papercut, do the following:

1. Follow the steps for adding an email account.
2. Continue with manual configuration in the wizard. (Automatic configuration does not work for local clients.)
3. Select the Send emails checkbox.
4. Select SMTP for the Protocol, and enter localhost for the Server host. Enter the Server port number (for example, 25).
5. Enter a random email ID and password on the login screen, and it will be configured.

5.5 Adding Attachments

To add attachments to the email message, do the following:

1. Create an Attachment entity. The Attachment entity extends the FileDocument entity by making it usable in all the places where the FileDocument entity is required.

   If you have a custom entity, you can extend it with the Attachment entity instead of FileDocument, or use the community commons DuplicateFileDocument function to create an Attachment from your custom entity.

2. Set the Attachment_EmailMessage association.

5.6 Page Styling

If the Email connector page styling is affected as you select and view email messages, it likely due to errors in the email message CSS. To resolve the errors, turn on Sanitize email to prevent XSS attacks in Account Settings.

5.7 Importing Emails with Long Attachment Names

Some email clients (for example, Gmail) break down the name of attached files if it is longer than a specific value, and add the file name in the Content Type for an attachment. This can cause an error while fetching or importing emails with long attachment names. For example: “ERROR - Email_Connector: Attribute ‘Email_Connector.Attachment.attachmentContentType’ has a maximum length of 200, tried setting a value of length xxx.”. This issue is resolved in version 5.3.0 of the Email Connector.

6 Known Errors

If you already have the included widgets in your app and they are not up to date, you may get a “Some widgets can not be read” error when trying to run locally.