MISSING_SUBJECT rule on email with subject

[Stephan Fourie]

Hi,

We're currently seeing the rule MISSING_SUBJECT sporadically hitting on 
emails that have a subject. This issue seems to have started during last 
week, which is when clients started complaining about false positive 
detections. Please see example headers at the following link:

https://pastebin.com/raw/GtnV67Hj

Has anyone seen the same or similar issue recently? If not, can anyone 
offer some advice or guidance?

Thanks!
Stephan