policyd, prepend and long lines

[Andreas Thienemann]

Hi,

I have a greylisting policy daemon running with postfix v3.2.2. This 
works nicely and when a mail is accepted, the policy daemon adds a 
header along the lines of "X-greylist: mail greylisted for {duration} on 
{hostname}."

This is done by sending "action=PREPEND header_text". This works nicely 
as well.

Earlier today I noticed that due to a change of the hostname, the header 
being added is now longer than 78 characters and is not folded according 
to RFC2822 rules.

That is unexpected. I fiddled a bit with the code and tried to do the 
folding in my policy daemon but was unsuccessful. A simple linebreak of 
course is interpreted as an end-of-line marker for the policy delegation 
protocol. And escaping the linebreak as \\n gives me a "\n" string in 
the header of the resulting mail, but no linebreak...

I had a look at some other open source implementations of policy daemons 
and it seems nobody has handled the case of long line headers.

Is there a good way of folding the header? Should postfix be doing that 
automatically already?

cheers,
 Andreas