I would like to rewrite an old-style header in a locally-generated mail (say by cron under Ubuntu 19.04 and earlier) e.g. From: r...@streamingbats.co.uk (Cron Daemon)
to the new-style header e.g. From: Cron Daemon <r...@streamingbats.co.uk> It must be done before milters so that it can be signed by opendkim milter after the header rewrite. canonical looks like the right tool but the examples I have seen only show it working on an address not the full header text. I am using postfix 3.3. Apart from cron, the only other local source of such old-style headers that I can find is postfix itself: e.g. From: mailer-dae...@streamingbats.co.uk (Mail Delivery System) - maybe more recent postfix releases use the new style?