[FIXED] How to Sign Javamail with DKIM

Issue

Is there a library or a way to do this without an external library? I am using apache james as my mail server and currently send email like this:

public void sendMessage(String to, String subject, String content) {
    MimeMessage message = new MimeMessage(session);
    try {
        message.addRecipients(Message.RecipientType.TO, to);
        message.setFrom(new InternetAddress(from));
        message.setSubject(subject);
        message.setContent(content, "text/html; charset=utf-8");
        Transport.send(message);
    } catch (MessagingException e) {
        e.printStackTrace();
    }       
}

But i'd like to sign the email with DKIM before hand. I understand I need to implement DKIM signing into the james server and plan on use jDKIM to do this, I also understand I need to create the keys using something like www.port25.com, but how do I actually sign the email in java before I send it out?

Solution

I ended up using DKIM for Javamail which can be downloaded at: DKIM For Javamail

Here is an example (Its pretty well documented in the examples in the download):

public void sendMessage(String to, String subject, String content) {
    //Create DKIM Signer
    DKIMSigner dkimSigner = null;
    try {
        dkimSigner = new DKIMSigner(properties.getProperty("mail.smtp.dkim.signingdomain"), properties.getProperty("mail.smtp.dkim.selector"), properties.getProperty("mail.smtp.dkim.privatekey"));
        dkimSigner.setIdentity(properties.getProperty("mail.user") + "@" + properties.getProperty("mail.smtp.dkim.signingdomain"));
        dkimSigner.setHeaderCanonicalization(Canonicalization.SIMPLE);
        dkimSigner.setBodyCanonicalization(Canonicalization.RELAXED);
        dkimSigner.setLengthParam(true);
        dkimSigner.setSigningAlgorithm(SigningAlgorithm.SHA1withRSA);
        dkimSigner.setZParam(true);
    } catch (Exception e) {
    e.printStackTrace();
        }
    if(dkimSigner != null) {
        //Create message
        Message message = new SMTPDKIMMessage(session, dkimSigner);
        try {
            message.setRecipients(Message.RecipientType.TO, InternetAddress.parse(to, false));
            message.setFrom(new InternetAddress(from));
            message.setSubject(subject);
            message.setContent(content, "text/html; charset=utf-8");
            Transport.send(message);
        } catch (MessagingException e) {
            e.printStackTrace();
        }   
    }           
}

Answered By - ryandlf

Answer Checked By - Marie Seifert (PHPFixing Admin)

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[FIXED] How to skip emails in copy operation for INBOX folder when emails already exist in java ?

Issue

I want to copy message from source mail server to destination mail server. i used imap protocol and javamail. For first stage, i copy message and there is not any problem. Again i copy message the already message dose not overwrite or skip copy. I want to skip message in inbox folder in the destination folder. I do not like delete source message. Thanks.

Solution

The most efficient way is to keep track of the UIDs of the messages from the source folder that you've already copied, so you don't copy them again. Depending on how you're doing the copying, you may only need to keep track of the last UID you copied, and then only copy messages with larger UIDs (newer messages). See the UIDFolder interface.

Answered By - Bill Shannon

Answer Checked By - Dawn Plyler (PHPFixing Volunteer)

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[FIXED] How to remove CC and BCC from Recipients address : JavaMail

Issue

I am able to add CC,BCC and TO successfully to message or Mimemessage, But my requirement is I need to send the constructed email to some third party for backup purpose. I Tried this:

message.setRecipient(Message.RecipientType.CC, null);
message.setRecipient(Message.RecipientType.CC, "");

Please help!!!

Solution

Use setRecipients instead of setRecipient, with a null address.

Answered By - Bill Shannon

Answer Checked By - Marilyn (PHPFixing Volunteer)

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