firewall

Juniper tends to have pretty good documentation in their knowledgebase, on how to configure equipment for different situations. I recently had to setup a VPN between a Juniper SSG-140 (at HQ) and a remote Cisco PIX. Going to Juniper's knowledgebase, you would most likely come across the article: http://kb.juniper.net/KB4147 . This article describes setting up a "route-based" VPN between the two devices. I believe these directions would work if you were trying to connect on subnet on each end.

Anti-virus and anti-spam protection at the firewall level is a growing trend, often referred to as Unified Threat Management. If you purchase one of the Juniper SSG Series firewalls, you can purchase subscriptions for “built-in” anti-virus and anti-spam UTM. Basically, you are allowed to attach these protections to an existing policy for scanning on inbound/outbound connections.
The anti-spam portion uses a Spam Block List (SBL) which is more commonly known as a Relay Block List (RBL). The SBL/RBL that Juniper offers is updated and maintained by Symantec and contains the Top 100 known spammers.
You can find a sample of the list at: http://www.juniper.net/security/spam/.

While the Top 100 known spammers is a good start, it still allows a lot of spam through which could be stopped/tagged. There is no way to add another SBL/RBL in the web GUI, but there is a hidden command in the CLI which will allow you to add other lists.