Jim Burt asked,
| With mail already on my computer in one large file, how can I send it through
| procmail? I look for an occasional one-time solution.
There's a script for that toward the end of the procmail(1) man page.
Here's a cheap boil-down that will do pretty much the same thing:
file=$1 #or plug it in by name
lockfile $file.lock
rawcount=`grep -c '^From ' $file`
formail -$rawcount -s procmail < $file
rm -f $file.lock
In case your .procmailrc has recipes that append a message to the file you're
working on, the -number option to formail makes formail stop where the input
file originally ended.