EMAIL-138: Do not automatically encode filename

[vrozkovec]

As of javax.mail 1.5.6, javax.mail.internet.MimeBodyPart contains the method
static void setFileName(MimePart part, String name)
that allows user to choose to encode the filename by MimeUtility.encodeText(name). Automatically encoding of filename should not be done in commons-email, but in javax.mail.

See issue https://issues.apache.org/jira/browse/EMAIL-138

[vrozkovec]

@markt-asf Hi, I've closed my previous PR and created new one, now without merge conflicts. Today I've again stumbled upon the same error when attaching filenames with UTF-8.
Thanks for consideration and eventual merge.

[xfh]

Hi @garydgregory, what is blocking this pull request? I'm also affected by this issue. Umlauts break due to the encoding.

If removing the encoding completely goes too far, how about enabling it conditionally as in javax.mail:
https://github.com/eclipse-ee4j/mail/blob/master/mail/src/main/java/javax/mail/internet/MimeBodyPart.java#L1296

This would fix two issues:
https://issues.apache.org/jira/browse/EMAIL-189
https://issues.apache.org/jira/browse/EMAIL-138

[Gragx]

https://issues.apache.org/jira/browse/EMAIL-181
Is yet another issue that would probably be solved by this