Mail Service Provider

From DreamHost

1 What is an MSP?
2 Why would I want to use an MSP
3 How to use an MSP with Dreamhost
4 Commercial MSPs

What is an MSP?

Mail Service Providers or "MSP"s provide enhanced services related to e-mail transport. MSPs typically provide outsourced services such as virus scanning, SPAM filtering and policy enforcement. MSPs typically do not host e-mail boxes. The primary purpose of an MSP is to provide a robust MTA for their clients' domains and to offload various e-mail processing tasks.

Why would I want to use an MSP

Due to their specialization, an MSP can provide improved e-mail handling, over and above Dreamhost's already excellent service. MSPs will be most attractive to business users who rely heavily on e-mail.

Reliability - MSPs maintain multiple, geographically diverse mail servers. The MSP will continue to accept mail for your domain in spite of regional outages. If Dreamhost's inbound mailservers are down (e.g. maintenance), the MSP will queue your mail for delivery once DH is back online.
Security - MSPs provide best of breed (often multi-sourced) anti-virus and also actively protect against e-mail bombs, directory harvest attacks, etc. If you are running your own mailserver, you can configure it to only allow connections from your MSP, thereby shielding it from many potential attackers.
SPAM filtering - MSPs provide best of breed (often proprietary) SPAM filtering and quarantine management systems.

How to use an MSP with Dreamhost

Sign up with an MSP. For budgetary purposes, you are probably looking at $3 to $5 per address per month with a minimum of 10 addresses. YMMV
In the Dreamhost Control Panel, go to Domains, Manage Domains and then click on the "DNS" link under the domain(s) that the MSP will be servicing.
Note your current MX settings. These are probably listed under the "Non-Editable" section with a type of "MX". You may need to provide this information to your MSP so that they know where to send your mail.
The MSP will provide you with new MX information. You will need to edit your MX records so that incoming mail will be directed to your MSP.
In the Dreamhost Control Panel, go to Mail, Custom MX. Scroll down to the section titled "Custom MX Records" and then enter the MX records provided by your MSP.
Check the "I still want Dreamhost to accept email for this domain" box.