Cloudweavers

I’ve been asked about the possibility of harnessing the power “of the cloud” in the context of an email server. For the simplicity of this blog post, I’ll assume the definition of “cloud computing” to be equivalent to “Amazon AWS” offer.

When emails goes in
This is the easy part. Receiving email in an EC2 (Elastic Cloud Computing) instance is as easy as receiving it anywhere. You launch 2 instances in different availability zone, grab 2 IP and change your MX records. With the recent availability of EBS (Elastic blocks store), you even have access to permanent storage for email. In hours (big maximum) you have a complete setup supporting fail-over and backup capability (leave your queue/data store on EBS for persistence and snapshot for backup).

Being in a full virtual environment also negate most scaling problems. You dynamically start and stop anti-{spam,virus} scanning instances following the need of your clients and customers. This setup is also very cost-effective: you don’t have to pay for hardware (servers, switches, hard drive..), maintenance, power and all the network management involved in having public infrastructure (bgp, firewall, etc…).You don’t even have to vouch for a long term contract.

For your customer, this represent a very decent offer: speed and latency in the Amazon cloud are very nice – way better than most small technical shop can afford.

Then emails have recipient
Emails are not only coming IN your infrastructure, they – sometime – must be transmitted to other people’s networks. This is where archaic email management style really fail. Emails as a services is a dynasty based on the conception that internet proprieties are big, controllable, static and permanent. This is the exact opposite of what you would get placing an email server inside Amazon Cloud.

You do not control IP space/range – even if, you are leased “1″ IP. This is the big “bug”. You have no idea what peoples do in their instances. Get used to it, your range will be tagged, {grey,black} listed often in dns based blocking list. Very often. White list will refuse your queries, since you cannot vouch for Amazon customer use of the cloud.

Solution, you can still use a smtp server install somewhere else, but… kind of defeat the whole purpose. The financial exercise of fighting dnsbl vs maintaining hardware infrastructure is left to the reader.