Martin,
Using the webform.pl, I get the following in my mail log:
Dec 19 15:14:22 mail sendmail[9689]: gBJEEMw09689:
Authentication-Warning: mail.jiffie.nl: nobody set sender to Hans using -f
Dec 19 15:14:22 mail sendmail[9689]: gBJEEMw09689: forward
/opt/OpenTRS//.forward.mail+: Group writable directory
Dec 19 15:14:22 mail sendmail[9689]: gBJEEMw09689: forward
/opt/OpenTRS//.forward+: Group writable directory
Dec 19 15:14:22 mail sendmail[9689]: gBJEEMw09689: forward
/opt/OpenTRS//.forward.mail: Group writable directory
Dec 19 15:14:22 mail sendmail[9689]: gBJEEMw09689: forward
/opt/OpenTRS//.forward: Group writable directory
Dec 19 15:14:22 mail sendmail[9689]: gBJEEMw09689: from=Hans, size=336,
class=0, nrcpts=1, msgid=<200212191414.gBJEEMw09689@mail.jiffie.nl>,
relay=nobody@localhost
Dec 19 15:14:22 mail procmail[9693]: Suspicious rcfile
"/opt/OpenTRS//.procmailrc"
Dec 19 15:14:22 mail sendmail[9692]: gBJEEMw09689: to=Misc