Spring MimeMessageHelper attachment filename encoding

Question

I am sending mail with MimeMessageHelper in my Spring Boot application.

How can I tell it to encode the filename, which contains the letter

Answer 1

I've solved the the problem with these lines:

• System.setProperty("mail.mime.splitlongparameters", "false")
• MimeMessageHelper helper = new MimeMessageHelper(message, true, "UTF-8")
• MimeUtility.encodeWord(attachmentFilename)

Here is the example code,

System.setProperty("mail.mime.splitlongparameters", "false");
MimeMessage message = sender.createMimeMessage();
MimeMessageHelper helper = new MimeMessageHelper(message, true, "UTF-8");

// Your email content
helper.setFrom("...");
helper.setTo("...");
helper.setSubject("...");
helper.setText("...");

helper.addAttachment(
    MimeUtility.encodeWord(attachmentFilename),
    attachmentContent
);