My objective is simple:
1. It has to be simple architecturally;
2. It has to be value-for-money;
3. Investment should be progressive, rather than huge up-front
It's in my character to think in the shoes of my customers when I introduce a product to them. That explains why I do not like to pay too much up-front, even though the money does not belong to me. Yes, revenue-wise it would be good for the company. However, I think I need to take a higher priority on my customers' interest.
When they grow big or even bigger, they'll always come back for us. So why worry about no recurring business?
Today, I found another interesting product from deepinvent Software GmbH - MailStore Server.
This product works very well with Microsoft Exchange. It is ideal for small companies. Actually it should work well for larger setup if the architecture is deployed correctly, my opinion.
So how about Sun Java Messaging Server?
MailStore Server comes with another component called MailStore Proxy. It can be deployed in front of the Sun Messaging Server.
The only change is to simply point your email client to this Proxy. All in-coming and out-going emails will now flow through the Proxy, thus achieving mail journaling objective.
Customer can choose to deploy this in-house if they like.
The pro-and-cons are discussed here.