CFMail attachment filename broken in ColdFusion 2016 on Windows server - coldfusion

Question

I'm moving a site from CF10 on Linux to CF2016 on Windows, and have run into an issue with file attachments with cfmail.
I'm attaching the file in cfmail with;
<cfmailparam file="#FileName#">
and have also tried variations with and without disposition and type like:
<cfmailparam file="#FileName#" disposition="attachment;
filename=""#FileName#"""
type="#ContentType#/#ContentSubType#">
But no matter what, on CF2016 on Windows, my attachments names in Outlook come through as ATT00160.dat (without type set) or ATT00169.xlsx (with type set)
It seems filenames over a certain length cause the issue. A filename of 64 characters will break it, but a smaller filename, of say 49 characters, won't.
Viewing the message source in Outlook, from the cfmail sent from Windows, I see the value below. Notice under content-type the name has been split?
Content-Type: application/octet-stream;
name*0=BLAH_BLAH1_Ownership_Database_Issue_2018-01_In_Development2.;
name*1=xlsx
Content-Transfer-Encoding: base64
Content-Disposition: attachment;
filename*0=BLAH_BLAH1_Ownership_Database_Is;
filename*1=sue_2018-01_In_Development2.xlsx
The same attachment sent with cfmail, from Linux, gives me:
Content-Type: application/octet-stream;
name=BLAH_BLAH1_Ownership_Database_Issue_2018-01_In_Development2.xlsx
Content-Transfer-Encoding: base64
Content-Disposition: attachment;
filename*0=BLAH_BLAH1_Ownership_Database_Is;
filename*1=sue_2018-01_In_Development2.xlsx
Note the content-type name has not been split.
Anyone have any ideas on how to fix this issue?

Answer 1

So, I finally sorted it. You need to manually put the file name in the type:
<cfmailparam file="#FileName#"
type="#ContentType#/#ContentSubType#;name=""#FileName#""">
I've never needed to do that previously. I don't know if this is a Windows server, CF2016 or SmarterMail (our mail server) thing, but if you run into the same issue, the above worked for me.

Answer 2

You might also see my report to Adobe Bug tracker. I have had trouble with long file name attachments ever since Coldfusion switched to the newer Javamail.
https://tracker.adobe.com/#/view/CF-4199784