After my SheevaPlug died, I was in search for a new (temporary) host. I decided on Amazon EWS, because it allowed me to set up my own server, use the software I want, and configure it the way I need to. The SheevaPlug itself was quickly repaired, but I decided to keep Amazon. Why? Because the server there is actually a bit faster then the SheevaPlug. Although the SheevaPlug could run dynamic web pages (such as this blog), it was not ideal, and pages loaded slowly. Most web pages were served statically.
But running Amazon EWS also has its disadvantages, especially with mail. The service offered by Amazon is great for spammers. You can set up a server, send all the spam, and cancel the account. For this reason, Amazon limits the number of mails you can send from an Amazon account. Even worse, many mail providers block all mail from Amazon. Hotmail is one such provider. If you try to send a mail to Hotmail, you get a quick message back, that mail is refused.
To solve this, I had to “split” the server. Web pages are still hosted at Amazon, but the mail server is hosted at the SheevaPlug. It was a bit complicated to set up, but it all works beautifully now. If a web page (on Amazon) now tries to send a mail, it used postfix. In postfix, the relay SMTP host is set to the web address of the SheevaPlug. So all mail is first send to the SheevaPlug, and only then to the addressee. The web mail is still hosted at Amazon, but it reads the mail from the SheevaPlug. Newly received mail is delivered directly to the SheevaPlug. This can be achieved by setting MX-1 DNS record.