command will still work. But it may create fake "From " lines which
are not the same as the originals.
+Alternatively, you might be able to suppress generation of the "From "
+line. If your procmail invocation includes the -f or -r option,
+remove. Those options add a "From " line to incoming beginning of
+messages that do not have them.
+
Here is a typical .procmailrc file for using procmail in conjunction
with nmh. For more information, see the manual pages for procmail,
procmailrc and procmailex.