The preceding section deals primarily with scanning incoming mail, but what about mail that you are sending? Does your antivirus program automatically scan it for viruses? Viruses and their writers are pretty sneaky; if your antivirus program scans files as they are created (the “automatic” protection), then you can be sure that outbound mail is virus-free.
That said, however, many antivirus programs do have a specific module that is “hooked in” to your e-mail program (again, just the “local” e-mail kinds like Outlook Express and Eudora) to scan each outbound message before it gets out of your computer. If you use Web-based e-mail, your ISP may be scanning your outbound mail automatically.
This is a good feature, because some e-mail programs don’t write your outbound messages to the hard drive until after they are sent. A plain-Jane antivirus program that is not e-mail aware would catch the virus, but only after your mail program had sent it out. This is precisely the reason why good antivirus programs specifically hook into your local e-mail program in order to detect and block outgoing viruses.