[Mimedefang] Folding headers?

[Damrose, Mark]

I've been having a problem with my internal Exchange 5.5 server crashing
randomly.  
The cause are messages that the Exchange considers "bad".  Microsoft's work 
around is to delete the problem message from the inbound queue and restart
the 
services.  Needless to say, this is quite annoying.

I suspect (but can't prove) that very long headers in some messages
contributing.
I've changed my filter to add headers to all messages that are scanned by
SpamAssassin, but not blocked as spam.

        action_change_header("X-Spam-Score", "$hits");
        action_change_header("X-Spam-Matches", "$names");
        action_change_header("X-Spam-Setting", "$req");

I suspect that the "X-Spam-Matches" header is getting too long when many low

value tests match, but it doesn't reach our threshold to block (8).

I am running v2.41 - planning to upgrade soon.

My questions.

Can MimeDefang automatically fold long headers?  
I've attempted to add spaces to the test names 
        $names =~ s/\,/\, /g;
but that doesn't seem to do it. 

Follow up question, If I have to fold the headers myself, will
action_add_header
or action_change_header change the standard \n end of line into an RFC 
compliant <CR><LF>, or do I need to explicitly insert them?