I added the line
to postfix_header_checks.in. When I issue a "postfix reload" as the zimbra user, I get...
/^To: .*recipients*/ REJECT Please disclose at least one recipient
and the header check doesn't work. What else can I be doing wrong? lol
postmap: warning: /opt/zimbra/conf/postfix_header_checks.ZkH361, line 5: record is in "key: value" format; is this an alias file?
EDIT: When removing my modification from the postfix_header_checks.in file, the postmap warning does not appear when doing a "postfix reload".