in the last couple days I've suddenly started receiving 'returned to sender' email, that I never sent, from email accounts that don't even exist on my account. I've checked and rechecked my personal PC and there are no viruses here. Is it possible that someone has hijacked my mail server account or something? or is it as simple as they are spoofing mail addresses to make it look like i'm sending spam (which I'm not). And how do I fix either of these problems. I've gotten aproximately 60 of these a day.

Hello,
it looks like the usual spam.

Best regards,
Slavik Koshelev

do you have some php script on a contact page or something ?
(like a form to send you mails from the web)

well yes. anyone who uses phpbb forums has this. but they aren't using any legitimate email address. its randomletters@mysticalkoala.com

Have you checked the Full headers of the mails ?

Oh well....PhpBB... the best target for novice web crackers and vandalism...

I'm comforted knowing my host is providing me with such secure software

also I need command line access to a standard UNIX type patch application to patch both my forums, is this something I can do or will I need someone there to do this?

You can ask for ssh access service to your account (for free), but I think you will have not the permissions to run a patch, but you can try , or you can ask Support guys to do it for you, they surely will help you (they has been all times very cooperative, at least on my own experience) with this task if you provide precise and detailed info about what to do.

My Invasion Invision Power Board doesn't cause problems. Just ask Hostony to put it in Fantastico for you. I have it on my server, for my customers.