Utility Features - MailMessage

Encrypting and Decrypting Messages

Aspose.Email provides facility to Encrypt and decrypt Email messages. This topic shows how an existing or new message can be loaded and encrypted using MailMessage. The encrypt() and decrypt() methods return the MailMessage object for the applied effects and needs to be taken care of while encrypting/decrypting messages. Encrypting and decrypting messages involves the following steps:

  1. Create a new message or load an existing one
  2. Encrypt the message using the certificate file
  3. Send the message or save it
  4. Decrypt the message as required

The following code snippet shows you how to encrypt and decrypt messages.

Checking a Message for Encryption

Aspose.Email MailMessage class allows checking a message if it is encrypted or not. The isEncrypted property of MailMessage allows checking this as shown in the following code sample.

Message Encryption with X509Certificate

Aspose.Email provides the API for working with Encrypted Messages with X509Certificate:

MailMessage class has the following methods to work with message encryption:

Configure Locale Options for Aspose.Email

You can use LocaleOptions class in case of unrecognised default locale and set most appropriate locale for Aspose Email lib. It offers the following methods to perform the task:

The following code sample demonstrates how to load a mail message from a file using the specified locale settings:

final Locale locale = new Locale("en", "DE");
Locale.setDefault(locale);

// set Locale for Aspose Email lib
LocaleOptions.setLocale("en-US");
// or
//LocaleOptions.setLocale(new Locale("en", "US"));

MailMessage.load("document.msg");

This code ensures that the application and the Aspose.Email library use the specified locales for handling language, country, and cultural conventions.

MailMessages Containing TNEF attachments

Transport Neutral Encapsulation Format (TNEF) is a proprietary email attachment format used by Microsoft Outlook and Microsoft Exchange Server. The Aspose.Email API allows you to read email messages that have TNEF attachments and modify the contents of them. The email can then be saved as a normal email or to the same format, preserving TNEF attachments. This article shows different code samples for working with messages containing TNEF attachments.

Reading a Message by Preserving TNEF Attachments

The following code snippet shows you how to read a message by preserving TNEF attachments.

Updating Resources in a TNEF Attachment and Preserving TNEF Format

The following code snippet shows you how to update resources in a TNEF attachment and preserve the TNEF format.

Adding New Attachments to Main Message Containing TNEF

Creating TNEF EML from MSG

Outlook MSGs sometimes contain information such as tables and text styles that may get disturbed if these are converted to EML. Creating TNEF messages from such MSG files allows us to retain the formatting and even send such messages via the email clients retaining the formatting. 

To create the TNEF, the following sample code can be used.

Detect if a Message is TNEF

Processing Bounced Messages

It is very common that a message sent to a recipient may bounce for any reason such as an invalid recipient address. Aspose.Email API has the capability to process such a message for checking if it is a bounced email or a regular email message. The CheckBounced method of the MailMessage class returns a valid result if the email message is a bounced email.

This article shows the usage of BounceResult class that provides the capability of checking if a message is a bounced email. It further gives detailed information about the recipients, action taken and the reason for the notification.

For a full guide to detecting bounces, reading DSN status codes and processing them in bulk, see Handling Bounce Messages and Delivery Failure Notifications.

Ignore exceptions

The library offers an ExceptionManager class to implement ignore exceptions ability into your application functionality. The code snippet below demonstrates how to set a callback to handle exceptions:

 ExceptionManager.setIgnoreExceptionsHandler( new IgnoreExceptionsCallback() {

   //exception path: {Module}\{Method}\{Action}\{GUID}

   //example: MailMessage\Load\DecodeTnefAttachment\64149867-679e-4645-9af0-d46566cae598

   public boolean invoke(AsposeException ex, String path) {

       //Ignore all exceptions on MailMessage.Load

       return path.equals("MailMessage\\Load");

   }

});

Or use an alternative:

 ExceptionManager.setIgnoreAll(true);

Also, you can set a callback for ignored exceptions log:

ExceptionManager.setIgnoreExceptionsLogHandler( new IgnoreExceptionsLogCallback() {

   public void invoke(String message) {

        System.out.println("=== EXCEPTION IGNORED === " + message);

   }

});

The user will be notified, that the exception can be ignored by an error message. For example:

Exception in message:

AsposeArgumentException: properties should not be empty.

If you want to ignore an exception and want to proceed further then you can use:

ExceptionManager.getIgnoreList().add("MailMessage\\Load\\DecodeTnefAttachment\\64149867-679e-4645-9af0-d46566cae598")

Invalid TNEF Attachment will be interpreted as regular attachment.

Bayesian Spam Analyzer

Aspose.Email provides the facility of e-mail filtering using the Bayes spam analyzer. It provides the SpamAnalyzer class for this purpose. This article shows how to train the filter to distinguish between the spam and regular emails based on the words database.

Obtaining Preamble and Epilogue from EML Messages

In the MIME format, the preamble is the text that appears after the headers and before the first multipart boundary. The epilogue is the text that appears after the last boundary and before the end of the message. This text is usually not visible to users in mail readers, but some MIME implementations may use it to insert notes for recipients who read the message using non-MIME-compliant programs.

The following code snippet shows how to obtain preamble and epilogue from an EML message which can be achieved with the corresponding methods of the MailMessage class:

// Gets or sets a preamble text.
public String getPreamble, setPreamble

// Gets or sets an epilogue text.
public String getEpilogue, setEpilogue

Display Optional Attendees in MHT Files

When working with the MHT format, you can display or hide information about optional attendees in the header of calendar events. To configure MhtSaveOptions for MHT file handling, you need to understand how the MhtFormatOptions.RenderCalendarEvent and MhtFormatOptions.WriteHeader values work:

  • MhtFormatOptions.RenderCalendarEvent - controls whether details of calendar events are rendered in the MHT file. By setting this option, you ensure that comprehensive event information, including attendee details, is included in the output.
  • MhtFormatOptions.WriteHeader - determines if headers containing metadata such as subject, date, and participant information (including optional attendees, when configured) are written into the MHT file.

The code sample below demonstrates how to use the display optional attendees feature when saving a message in MHTML format:

MhtSaveOptions options = new MhtSaveOptions();
options.setMhtFormatOptions(MhtFormatOptions.RenderCalendarEvent | MhtFormatOptions.WriteHeader);

MailMessage eml = MailMessage.load("meeting.msg");
eml.save("meeting.mhtml", options);

If you need to exclude information about optional attendees from the MHT file, clear the format template for the optional attendees before saving:

MhtSaveOptions options = new MhtSaveOptions();
options.setMhtFormatOptions(MhtFormatOptions.RenderCalendarEvent | MhtFormatOptions.WriteHeader);

// Skip the optional attendees in the MHTML output
options.getFormatTemplates().set_Item(MhtTemplateName.OPTIONAL_ATTENDEES, "");

MailMessage eml = MailMessage.load("meeting.msg");
eml.save("meeting2.mhtml", options);

Save All Headers in MHTML

The SaveAllHeaders property of the MhtSaveOptions class defines whether all headers should be written to the output MHTML or not. The following code snippet shows you how to save all headers of a message into an MHTML file:

MailMessage eml = MailMessage.load("message.eml");

MhtSaveOptions sopt = SaveOptions.getDefaultMhtml();
sopt.setSaveAllHeaders(true);

eml.save("message.mhtml", sopt);

Email Tracking using MDN and Read Receipts

Aspose.Email API provides support for email tracking using Message Disposition Notification (MDN). This is achieved by requesting read receipts and creating the required information:

  • MailMessage.setReadReceiptTo(MailAddressCollection) sets the read receipt addresses.
  • MailMessage.createReadReceipt(String, String) builds a read receipt for a received message.
  • MapiMessage.setReadReceiptRequested(boolean) sets whether a read receipt is requested for an Outlook message.

The following code snippet shows you how to track email using the Aspose.Email API:

try (SmtpClient client = new SmtpClient("smtp.server.com", 587, "username", "password")) {

    // Send a message with a requested read receipt
    MailMessage mailMessage = new MailMessage("from@domain.com", "to@domain.com",
            "test MDN", "This is a test message with read receipt requested");

    MailAddressCollection readReceiptTo = new MailAddressCollection();
    readReceiptTo.add("from@domain.com");
    readReceiptTo.add("another@domain.com");
    mailMessage.setReadReceiptTo(readReceiptTo);

    client.send(mailMessage);

    // On the recipient side: check the request, then create and send the read receipt
    MailMessage emlMDN = MailMessage.load("received.eml");
    if (emlMDN.getReadReceiptTo().size() > 0) {
        client.send(emlMDN.createReadReceipt("to@domain.com", null));
    }
}

A read receipt can also be requested on an Outlook message:

// Create a MapiMessage with a requested read receipt
MapiMessage mapiMessage = new MapiMessage("from@domain.com", "to@domain.com",
        "test MDN", "This is a read requested mapiMessage", OutlookMessageFormat.Unicode);
mapiMessage.setReadReceiptRequested(true);

// Or create a MailMessage with a requested read receipt and convert it to a MapiMessage
MailMessage mailMessage = new MailMessage("from@domain.com", "to@domain.com",
        "test MDN", "This is a test message with read receipt requested");

MailAddressCollection readReceiptTo = new MailAddressCollection();
readReceiptTo.add("from@domain.com");
mailMessage.setReadReceiptTo(readReceiptTo);

MapiMessage converted = MapiMessage.fromMailMessage(mailMessage, MapiConversionOptions.getUnicodeFormat());
Loading and Saving Messages Track Document Conversion Progress