Database Software

Let me see if I understand...

You say that the correctly encoded filename "doesn't work". In what sense does it not work?  Exactly what fails and how does it fail?

Are you asking to violate the MIME spec and use more than 75 characters per encoded word?  No, there's no way to force JavaMail to do that.  Are you doing that because your message is being processed by some program that doesn't implement the MIME spec correctly?  Maybe that other program is the thing that needs to be fixed?

Thanks Bill for the comments. The issue is if the lengthy encoded word (>75 characters) is passed without including the CRLF spaces then it works fine in Outlook and Gmail but it does not work by sending the lengthy filename using MimeUtility.encodeText() API.

Eg:

//The below code does not work to send the attachment and the attachment name is displaying the UTF-8 characters

String fileName="ÀÁÅÆÀÁÅÆÇÈÉÊËÌÍÎÏÐÀÁÅÆÇÈÉÊËÌÍÎÏÐÑÒÓÔÕÖØÙÚÛÜÝÞßàáâãäåæçèéêëìíîïðñòóôõöøùúûüýþÿÀÁÅÆÇ.doc";

messageBodyPart.setFileName(MimeUtility.encodeText(fileName, "utf-8",null));

//The headers are displayed in Gmail as:

Content-Type: text/plain; name="=?utf-8?B?w4DDgcOFw4bDgMOBw4XDhsOHw4jDicOKw4vDjMONw47Dj8OQw4DDgcOF?="

=?utf-8?B?w4bDh8OIw4nDisOLw4zDjcOOw4/DkMORw5LDk8OUw5XDlsOYw5nDmsObw5w=?=\

\

=?utf-8?B?w53DnsOfw6DDocOiw6PDpMOlw6bDp8Oow6nDqsOrw6zDrcOuw6/DsMOx?=\

\

=?utf-8?B?w7LDs8O0w7XDtsO4w7nDusO7w7zDvcO+w7/DgMOBw4XDhsOHLmRvYw==?="; charset=us-ascii

Content-Transfer-Encoding: 7bit

Content-Disposition: attachment; filename="=?utf-8?B?w4DDgcOFw4bDgMOBw4XDhsOHw4jDicOKw4vDjMONw47Dj8OQw4DDgcOF?=\

\

=?utf-8?B?w4bDh8OIw4nDisOLw4zDjcOOw4/DkMORw5LDk8OUw5XDlsOYw5nDmsObw5w=?=\

\

=?utf-8?B?w53DnsOfw6DDocOiw6PDpMOlw6bDp8Oow6nDqsOrw6zDrcOuw6/DsMOx?=\

\

=?utf-8?B?w7LDs8O0w7XDtsO4w7nDusO7w7zDvcO+w7/DgMOBw4XDhsOHLmRvYw==?="

==============================================

//The below code works and attachment name shows correctly: [Custom generated Base64 code for filename]

String fileName="ÀÁÅÆÀÁÅÆÇÈÉÊËÌÍÎÏÐÀÁÅÆÇÈÉÊËÌÍÎÏÐÑÒÓÔÕÖØÙÚÛÜÝÞßàáâãäåæçèéêëìíîïðñòóôõöøùúûüýþÿÀÁÅÆÇ.doc";

String encodedName = "=?utf-8?B?w4DDgcOFw4bDgMOBw4XDhsOHw4jDicOKw4vDjMONw47Dj8OQw4DDgcOFw4bDh8OIw4nDisOLw4zDjcOOw4/DkMORw5LDk8OUw5XDlsOYw5nDmsObw5zDncOew5/DoMOhw6LDo8Okw6XDpsOnw6jDqcOqw6vDrMOtw67Dr8Oww7HDssOzw7TDtcO2w7jDucO6w7vDvMO9w77Dv8OAw4HDhcOGw4cuZG9j?=";

messageBodyPart.setFileName(encodedName);

//The message header in Gmail:

Content-Type: text/plain; name="=?utf-8?B?w4DDgcOFw4bDgMOBw4XDhsOHw4jDicOKw4vDjMONw47Dj8OQw4DDgcOFw4bDh8OIw4nDisOLw4zDjcOOw4/DkMORw5LDk8OUw5XDlsOYw5nDmsObw5zDncOew5/DoMOhw6LDo8Okw6XDpsOnw6jDqcOqw6vDrMOtw67Dr8Oww7HDssOzw7TDtcO2w7jDucO6w7vDvMO9w77Dv8OAw4HDhcOGw4cuZG9j?="; charset=us-ascii

Content-Transfer-Encoding: 7bit

Content-Disposition: attachment; filename="=?utf-8?B?w4DDgcOFw4bDgMOBw4XDhsOHw4jDicOKw4vDjMONw47Dj8OQw4DDgcOFw4bDh8OIw4nDisOLw4zDjcOOw4/DkMORw5LDk8OUw5XDlsOYw5nDmsObw5zDncOew5/DoMOhw6LDo8Okw6XDpsOnw6jDqcOqw6vDrMOtw67Dr8Oww7HDssOzw7TDtcO2w7jDucO6w7vDvMO9w77Dv8OAw4HDhcOGw4cuZG9j?="

Query - Is it OK to use the above working code?

Ok, I see the problem.

You shouldn't be encoding the filename yourself using MimeUtility.encodeText because JavaMail will detect it as a parameter value that includes CRLF and will add escapes.  You should just call messageBodyPart.setFileName(fileName).

That will let JavaMail encode the filename itself, using RFC 2231 (assuming you're using the current version of JavaMail).  Or, if the mailers you're using don't support that encoding, you should configure JavaMail to use the non-standard MIME encoding for filenames by setting the System properties "mail.mime.encodefilename" to "true" and "mail.mime.encodeparameters" to "false".