An attachment is rendered as a *.dat file due to the sending server splitting the long attachment name into parts

An attachment is rendered as a .dat file due to the sending server splitting the long attachment name into 2 parts.

name*xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx;
name*xxxx.pdf

when it should only be:
name=xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx.pdf

When support tried to telnet the mail's page source as is: The issue can be reproduced - we can see the attachment being rendered as a .dat file.

When support tried to telnet the mail's page source changing the filename of the attachment from:

name*xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx;
name*xxxx.pdf

to

name=xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx.pdf

The attachment is being rendered correctly as a .pdf file.

This has been reproduced on 2 different domino servers. Version 901.

Note: Even though the attachment is rendered as a .dat file, when you double click on it, it still opens as a pdf.

The company that owns the sending server reported that they upgraded their code to adhere to the RFC standards:

https://tools.ietf.org/html/rfc2045
https://tools.ietf.org/html/rfc2231

According to rfc2231:

(1)   Lines in Internet email header fields are folded according to RFC 822 folding rules.  This makes long parameter values problematic.
 
SPR # MJTMAPNP5K  - Reporting this issue as an enhancement request