Re: [exim] Adding Headers in a filter

Luca Bertoncello wrote:
> Hi, list!
>
> I'm trying to write a filter for Exim 4.67, that, if some conditions are true,
> it adds an Header to the E-Mail.
> Unfortunately, Exim says, I can do that only in System-Filter.
>
> Has someone an idea, how can I force Exim to do what I want?
>
> Thanks
> Luca Bertoncello
> (lucabert@???)
>
>

No need to 'force' Exim. Just nibble the ears gently...

- You can add (or remove) headers in the 'aleter' acl's or in router/transport sets.

You cannot add headers during initial 'connect', 'helo/ehlo'. 'mail-from', or
'recpt-to' phases because there is not yet a message in the hands of the MTA to
hang them on - only a negotiation as to whether a message can be conveyed.

In some cases, added headers behave as if they were flags or buffers being
carried along for final 'recording' at a later stage, so have a care when taking
action on a header that it is/is not actually locked-in yet.

Give some thought to using custom X-headers to do whatever you need - then
removing them as the last stage of off-box transfer.

That keeps messages cleaner, neater, a line or several shorter, reduces risk of
conflict with header titles used by others, makes any special steps you are
taking less visible.

Bill