This is for Exchange 2007 and 2010 ONLY. For the version for Exchange 2003, click here: Filter Out Mail to Non-Existent Users - Exchange 2003
Being able to filter out email for non-existent users is a key configuration for modern email servers. This can have a significant effect on the amount of email that the server has to process and ensures that you are not a cause of backscatter, which can lead to the server being blacklisted.
The rejection is done at the SMTP level - so the email message isn't even delivered. If valid senders misspell an email address then they will get a bounce message immediately - indicating that the message has been rejected.
The ability for Exchange 2007 to drop email for unknown recipients is available as part of the anti-spam functionality, but this is only installed by default on the Edge Server role and on SBS servers. For a deployment without an Edge server you need to install the anti-spam agents manually on the Hub Transport servers. If you are using multiple hub transport servers then they need to be installed on everyone that is internet facing. This is done by using a PowerShell script supplied with the server.
Anti-spam Controls Installation.
- In The Exchange Management Shell, change to the following directory (presuming default installation location) C:\Program Files\Microsoft\Exchange Server\Scripts
- Use tab to select install-AntispamAgents.ps1 and press enter.
- Once it has completed, restart the Microsoft Exchange Transport Service, then restart the Exchange Management Console and go in to Organisation Configuration, Hub Transport and select the Anti-spam tab.
Enable Recipient Filtering.
- All of the anti-spam options are enabled by default. For now, disable them all except for recipient filtering.
- Go in the the properties of recipient filtering and enable the option "Block messages sent to recipients not in the global address list" on the Blocked Recipients list. Apply/OK out.
- Restart the Microsoft Exchange Transport Service again.
Tarpit
With Exchange 2003 you needed to enable the tarpit to protect against directory harvest attacks. That is not required with Exchange 2007 and higher as tar pit is enabled by default.
Exchange 2007 Home Page - Site Home Page
Last Page Update: 15/09/2011
| More Content from Sembee Ltd. | ||
| Resources on exchange.sembee.info | Other Sites | Sembee Ltd. |
| Microsoft Exchange 2003 | Command Prompt Getting Started Guide | Microsoft Exchange Consultancy |
| Microsoft Exchange 2007 | Login Scripts | Director's Blog |
| Microsoft Exchange 2010 | MS Exchange Resources | |
| Microsoft Outlook | Knowledge Base search | |
| Exchange Networking Tasks | Recovery of MS Office content from Temp Files | |
| Amazon Store | Troubleshoot the Automatic Updates Client | |
| UK ISP Status Pages | ||
| © Sembee Ltd. 1998 - 2011. | ||
| Reproduction of any content on this web site is prohibited without express written consent. Use of this web site is subject to our terms and conditions. All trademarks and registered trademarks are property of their respective owners. This site is not endorsed or recommended by any company or organisation mentioned within and is to provide guidance only and as such we cannot be held responsible for any consequences of following the advice given.
Sembee Ltd. is registered in England and Wales at 33 Scrivens Mead, Thatcham, Berkshire, RG19 4FQ. | ||