[ILUG] script process mboxes add headers

[Lars Hecking]

> Does anyone know how to process all messages in a mbox, taking the data 
> from the message-id header and adding it to a new X header?

 I think it's a bit more complicated than what you outlined: you need to run

 formail -s procmail -m rcfile <inbox >output

 to split the inbox into single emails and let procmail process each
 individually with the recipe(s) in rcfile. The procmail recipe will
 extract the message-id: header, and then use formail to append or
 insert the new XUIDL header. Something along the lines of
 (completely untested)

 :0 fwh
 * ^Message-ID: \/[^ ]*
 |formail -I "X-UIDL: $MATCH"

 give or take a few flags or options.