Questions[virtual-hosting](server)

I've been wanting SSL for one portion of my website, which is one single domain name on my VPS.

As most certificates look fairly expensive, I had looked at my domain name provider and had found a fairly good deal: http://www.dynadot.com/ssl/about.html

I would be looking at the AlphaSSL one of which provides an intermediate (chained) certificate for me to install I assume which is what I wish for.

I however have started to host a few small project websites for users and had started to wonder if I could possibly use this certificate for them as well, as it is on the same physical host and IP address, just differing by top level domain name that they give me.

Would I be able to install the certificate for all of them with this AlphaSSL certificate?

Also, would I be able to use this freely for imaps (especially as the domain names are not part of the picture) and secure all my IMAP users?

I've been searching for a resource on how to do this but not having much luck.

I am running a working MTA/MUA that is based on Postfix and Courier with MySQL as a backend for virtual users. I based my system on the following article:

https://help.ubuntu.com/community/PostfixCompleteVirtualMailSystemHowto

It was great up until the empty sections! My SMTP/IMAP setup is working great, and I managed to get SpamAssassin and ClamAV installed as well with some separate documentation I found online.

What I need help with is setting up Postfix to use Procmail as the mailbox_command so that it will work with virtual users. I want to be able to define different Procmail rules for each virtual user separately. I've read the Postfix documentation, and as I understand it the default functionality for mailbox_command will only work for local (non-virtual) users.

Thanks in advance!

UPDATE:

Since this post, I've come to realize that mailbox_command is not tenable. Instead I found a way to do this using transport_maps. Read my own answer below.

Need Advice which sharing hosting will run Magento Community fast or some other not expensive solution.

This website will not have a lot of users, I only need that it will run fast for 100-20 users in same time. The problem with magento is database design that make this system very slow , also other staff not the best.

I had hostmonster.com and justhost.com for previous website but it wasn't fast enough for single user that not located in USA (my customer areas: Asia, Africa). each action that involve database takes a lot of time.

Thanks