CODEWITHSUNDEEP
javajakarta-mailimap
Ronak Jain
Ronak Jain

Reputation: 2440

Unable to get message_ID for MimeMessage

I have a java program using Java Mail-1.5 that fetch and process message(email) of Gmail(IMAP). It works fine for most of the case, but for few messages when I try to get message_id using MimeMessage, it is giving me NULL. In that case I am not able to process the messages as messageID is unique for the messages.

String messageID = ((MimeMessage) msg).getMessageID(); //NULL for few messages.

Is there any other way to get message Id as I don't want to ignore such messages.

Upvotes: 4

Views: 2395

Answers (3)

Stavr00
Stavr00

Reputation: 3314

Use this to force JavaMail API to refresh the headers from the content.

((MimeMessage) msg).saveChanges();

It should populate the Message-ID header value. The following example is a simple way to generate message IDs at will:

MimeMessage mimemessage 
            =new MimeMessage(Session.getDefaultInstance( new Properties()));
mimemessage.saveChanges();
String messageID = mimemessage.getMessageID();

Upvotes: 3

Bill Shannon
Bill Shannon

Reputation: 29961

Messages are not required to have a Message-Id header. Most messages do. And in many cases, if a server receives a message without a Message-Id header, it will add one. Still, there are no guarantees. If you're depending on the Message-Id to uniquely identify a message, you need to have a fallback technique for the cases where the message doesn't have a Message-Id.

Upvotes: 3

Keerthivasan
Keerthivasan

Reputation: 12880

String messageID = ((MimeMessage) msg).getMessageID();

Returns null if this field is unavailable or its value is absent.

You can create your own message id if it is null

StringBuffer s = new StringBuffer();
if(messageId == null)
messageId =  s.append(s.hashCode()).append('.').append(getUniqueId()).append('.').
append(System.currentTimeMillis()).append('.').
append("JavaMail");

This is how message id is created and set when a mail is being sent. You can go with your own implementation based on your requirement and then proceed to process your message

Upvotes: 2

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