I have a Google Apps account set up for my domain with catch-all enabled. Recently I've been receiving bounced mail that I didn't send from random aliases for my domain (for example,
C03481751@mydomain.com) with account names such as "BuyVigara Today", so I guess someone is using my domain to spam.
I have disabled the option in the Google Apps control panel that says
Allow users to send mail through an external SMTP when configuring a "from" address hosted outside your email domains thinking that was the issue, but I'm still getting the bouncebacks. I've also changed the passwords for all accounts in the domain.
Here is an example of one of the bouncebacks (with emails removed for privacy):
MailEnable: Message could not be delivered to some recipients. The following recipient(s) could not be reached: Recipient: [SMTP:***@verizon.net] Reason: Remote SMTP Server Returned: 550 5.1.1 unknown or illegal alias: firstname.lastname@example.org Message headers follow: Received: with MailEnable Postoffice Connector; Fri, 7 Sep 2012 13:17:56 -0400 Received: from ([18.104.22.168]) by vstaticip.com with MailEnable ESMTP; Fri, 7 Sep 2012 13:17:55 -0400 From: "BuyVigara Today" <C03481751@***.com> To: <***@***.com> Subject: Friday sales Date: Fri, 07 Sep 2012 12:17:58 -0500 MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 8bit List-Unsubscribe: <mailto:886B315F805F9DA0480DB38@soltecventures.com> Message-ID: <20120907121758.255564C230A99B6A4E65@DANIEL-PC> X-ME-Content: Deliver-To=Junk X-ME-Bayesian: 0.000913
Any suggestions as to how this can be prevented?