Over the last two weeks, I've started receiving many emails from unknown email addresses, complete with virus attachments.

My AV software is up to date, and has been detecting and deleting the virus files. I use Outlook Express V6, and have been using the "block sender" facility to stop further emails, but more still come.

I assume that new sender email addresses are being used to avoid the blocking. This morning I found about 30 infected emails waiting for me when I started to receive emails in OE. Common sender names have words to do with Microsoft, Postmaster. The addresses don't have names that I recognise.

Please tell me what is going on, and what is the best way to stop getting these emails.

Geoff Hales, Kenmore, NSW

As you surmise, the infected emails transmitted from infected computers have an infinite variety of sender addresses (fake). There are a couple of things you can do to reduce the flow.

If you're using Outlook Express, you can use the Rules Wizard to block all mails with attachment larger than 140 KB and smaller than 170 (the Swen virus attachments fall within this range) and delete them from the server without downloading.

Another way is to install Mailwasher. This excellent product displays e-mails on your server without downloading them, and if they have attachments in the size range I mentioned, and pretend to come from Microsoft, you can delete them from the server without downloading.

The flood will abate when all infected systems that know about your e-mail address have sent off their missiles; they are only sent once to each address. I received over 900 Swen mails but lately I haven't seen one.

As long as you keep deleting them, you're safe. It also helps to make sure your Windows is up to date, using the proper Windows Update function on your Start menu; the Swen virus can't invade an up-to-date system.

Jan Wikström