hello, hope i'm in the right forum. i try to find a way to add some custom header to the incoming mail. so i create /etc/postfix/my_custom_header with this line: /^X-Original-To: (.*)$/ PREPEND X-Original-dest: $1 but when i reload postfix i have a mail error: Postfix SMTP server: errors from mail.***.com .... all i want, is to add a line 'X-Original-dest' in header with the mail adress of X-Original-To cause in all header, i have twice X-Original-To, the first are the right, but the second is with the "To:" address . i have a account firstname.lastname@example.org without mailbox who forward to user1 and user2 . user1 and user2 don't have a mailbox, but there's a collector for mails without user account. so when i send mail to email@example.com, i receive two mail in firstname.lastname@example.org. header example: Return-Path: <email@example.com> X-Spam-Checker-Version: xxxxx xxxxx X-Spam-Level: xxxxxxxxxxxx X-Spam-Status: xxxxxxxxxxxxxxxxxxxxxx HTML_MESSAGE xxxxxxxxxxx X-Original-To: firstname.lastname@example.org Delivered-To: email@example.com Received: by xxxxxxxxxxxxxxx (Postfix, from userid xxx) DomainKey-Status: good X-Original-To: firstname.lastname@example.org Delivered-To: email@example.com From: "[NC] me" <firstname.lastname@example.org> To: <email@example.com> Subject: test can someone help me please.