The problem
I have multiple email addresses and a Google calendar.
I sync the Google calander with my PC, laptop and iPhone. On my Linux PC and laptop I use Thunderbird to sync my calendar and on my iPhone 4 the standard Apple calendar app as pre-installed on the iPhone.

This brief guide will explain the steps you can take to get basic SMTP AUTH working with Debian Sarge's exim4 package. (For users connecting to your server, not for forwarding via your ISP)

First of all generate an Exim SSL certificate:

Last week I would change the SMTP port from my Exim4 email server in Amsterdam.

Why?

I am using my laptop on many network over many providers. Also the network from ziggo.nl in The Netherlands that blocked all SMTP (port 25) traffic outside here one network.