Generally people who share virus warnings are well meaning. However, it is a good idea to get into the habit of religiously running Norton Anti Virus, or McAfee or whatever your A/V program of choice is, and download updates weekly if the maker of your program provides them. (I know Norton does.)
You should also download a copy of Zone Alarm (free) or spring a few bucks for their newer version of Zone Alarm Pro.
In addition to being a very user friendly, and self configuring firewall program to prevent unwanted hacker intrusions into your computer, the Pro version also quarantines any suspicious attachments arriving in e-mail, preventing you from accidentally opening them. The list of attachments including files that end with the extension "exe", "com", "bat", "vbs", etc....can also accept manual input of any other extensions you want to add, so that when you see a new virus warning you can add the extension name to the list, if it's one the program doesn't already have on file. This program is really a must for anyone connected permanently to the Internet via cable, ISDN, DSL, T1, or T3 etc. You will be astounded at the number of blcoked intruder attempts in a 24 hour period, when you first get it.
Lastly, it seems that the vast majority of e-mail based viruses are written specifically for Microsoft Outlook and Outlook Express. If you don't mind a slight learning curve, and want more piece of mind with your email, download Eudora and start using it instead. It is a much more secure email program, and not susceptible to the majority of viruses targeted towards Outlook, and it is a stand-alone, non integrated program. It has numerous features not found in Outlook and is considered a much better email program than Outlook by the majority of PC magazines.