Please choose one of the following vpopmail installation options:

I would like to install vpopmail without MySQL intregation
(recommened for smaller email servers and for qmail/mysql newbies)

or

I would like to install vpopmail with MySQL integration
(I do not use MySQL integration and thus have not updated this part of the guide, please goto qmailrocks.com for the official guide)
(Requires that mysql server be installed on your server. Recommended for larger email servers & ONLY for experienced mysql users)

Which option is best for me?

First of all, don't feel that a vpopmail installation without mysql is somehow inferior or inadequate. It's not. The choice of whether or not to use mysql with vpopmail, in my opinion, is a personal preference and basically comes down to 2 things:

1. How large is you mail server going to be?

If you are only planning on hosting a handful of domains on your mail server, I don't think it's really worth integrating mysql into it. I have a server that hosts about 50 domains on it right now and it does NOT have mysql integrated into vpopmail. It works perfectly fine. The qmailrocks.org mail server also does NOT have mysql built into it. It runs great. However, if you plan to host more than 50 domains or so, I'd say go with mysql. It  makes it easier to manage a lot of domains and also makes porting the mail server to new equipment and locations easier. Of course, the decision is up to you. If you really want to use vpopmail with mysql on a server that hosts only 1 domain, knock yourself out. My opinion though, is that unless you are hosting a ton of domains, integrating mysql into vpopmail is simply making your mail server more complex than it needs to be. And as we all know, the more complex the plumbing, the easier it is to stop up the drain.

2. How comfortable are you with mysql?

If you're a newbie and you don't know jack shit about mysql, don't be a jackass. Just use the default vpopmail installation and save yourself the aggravation. I can't hold you hand though installing and setting up mysql, and you'll be hard pressed to find someone else that will. In short, don't get in over your head.