Does it support more than 255 characters?
MIME spec says about encoded-word as:
An encoded-word may not be more than 75 characters long, including charset, encoding, encoded text, and delimiters. If it is desirable to encode more text than will fit in an encoded-word of 75 characters, multiple encoded-words (separated by CRLF SPACE) may be used.
But can we pass the encoded filename as shown below to avoid the extra new line, spaces generated by encodeText() API?
"=?utf-8?B or Q?long_encodedtext?=" [Instead of breaking it into multiple lines]
Eg:
filename="=?utf-8?B?w4DDgcOFw4bDgMOBw4XDhsOHw4jDicOKw4vDjMONw47Dj8OQw4DDgcOFw4bDh8OIw4nDisOLw4zDjcOOw4/DkMORw5LDk8OUw5XDlsOYw5nDmsObw5zDncOew5/DoMOhw6LDo8Okw6XDpsOnw6jDqcOqw6vDrMOtw67Dr8Oww7HDssOzw7TDtcO2w7jDucO6w7vDvMO9w77Dv8OAw4HDhcOGw4cuZG9j?=" [It works and the base64 is generated by custom code]
The following does not work and generated by MimeUtility.encodeText() API.
Content-Disposition: attachment; filename="=?utf-8?B?w4DDgcOFw4bDgMOBw4XDhsOHw4jDiQ==?=\
\
=?utf-8?B?w4rDi8OMw43DjsOPw5DDgMOBw4XDhsOH?=\
\
=?utf-8?B?w4jDicOKw4vDjMONw47Dj8OQw5HDksOT?=\
\
=?utf-8?B?w5TDlcOWw5jDmcOaw5vDnMOdw57Dn8Og?=\
\
=?utf-8?B?w6HDosOjw6TDpcOmw6fDqMOpw6rDq8Os?=\
\
=?utf-8?B?w63DrsOvw7DDscOyw7PDtMO1w7bDuMO5?=\
\
=?utf-8?B?w7rDu8O8w73DvsO/w4DDgcOFw4bDh8OIw4nDisOLw4zDjcOOw4/DkC5kb2M=?="