Possible Duplicate: How could I prevent my mail from being recognized as spam? I'm sending a newsletter with drupals simplenews module The website is hosted on an 1und1 server in germany (as seen in in header domains online.de and kundenserver.de) When I send it, it goes to Spam folder in Yahoo & GMail Mailbox, but not in Spam Folder in web.de, hotmail and GMX Mailboxes Here is, what I have in the Mail Header (for yahoo in this example) Received: from 12.345.678.90 (EHLO sXXXXXXXXX.online.de) (12.345.678.90) by mtaXXX.mail.kks.yahoo.co.jp with SMTP; Fri, 15 Jun 2012 18:45:24 +0900 Received: from [127.0.0.1] (helo=infongdXXXXX.rtr.kundenserver.de) by sXXXXXXXXX.online.de with esmtp (Exim 4.72) (envelope-from <[email protected]>) id 1SfT5k-00068r-Q8 for [email protected]; Fri, 15 Jun 2012 11:45:20 +0200 Received: from 83.136.130.41 (IP may be forged by CGI script) by infongdXXXXX.rtr.kundenserver.de with HTTP id 0Z04SW-1SQTKp3LPr-00YxYk; Fri, 15 Jun 2012 11:45:20 +0200 From: SENDER <[email protected]> To: "[email protected]" <[email protected]> Date: Fri, 15 Jun 2012 11:45:20 +0200 Subject: This is the subject of the newsletter Thread-Topic: This is the subject of the newsletter Thread-Index: Ac1K3nT42juzo7uCSkq5dTlby1ZvpQ== List-Unsubscribe: <http://www.example.com/newsletter/confirm/remove/XXXXXXXXX> X-MS-Has-Attach: X-Auto-Response-Suppress: All X-MS-TNEF-Correlator: x-originating-ip: [12.345.678.90] authentication-results: mtaXXX.mail.kks.yahoo.co.jp from=example.com; domainkeys=neutral (no sig); dkim=neutral (no sig) [email protected] errors-to: "SENDER" <[email protected]> received-spf: none (sXXXXXXXXX.online.de: domain of [email protected] does not designate permitted sender hosts) x-apparently-to: [email protected] via 123.45.67.890; Fri, 15 Jun 2012 18:45:25 +0900 x-sender-info: <[email protected]> content-length: 13762 Content-Type: multipart/alternative; boundary="_000_7471797868716571796675707173696675806577726778666766687_" MIME-Version: 1.0 I cannot see any direct spam filter message in this. But I'm kind of stunned by the Received: from 83.136.130.41 (IP may be forged by CGI script) part. After I searched a bit, it seems, that this is a special 'feature' of 1und1 Mail servers. Here are my questions: Is it possible that, if I get rid of the 'Ip maybe forged' part, that the Mail is not regarded as spam anymore? If so, Does anyone know, how I can get rid of it in drupal?