On this page, you can find information about Opus One's virus scanning technology.

Opus One is scanning incoming for virii in end user email which is delivered through our email system. This isn't as easy as it sounds: there are lots of ways for mail messages to be packed up, labelled, compressed, and sent over the Internet. While a message is in-transit through an email system, it's not so easy to tell whether it has a virus. In addition, different people use different computers, so a virus which might affect a Windows user would probably not bother a Macintosh or Unix user.

Our virus scanner only looks at messages which have been sent in over the Internet; messages originating on the Opus One network being sent to Opus One customers will not be scanned. Our scanner also only looks at messages which are incoming to Opus One. Messages sent outbound through our mail servers are not scanned for viruses.

Opus One virus scanning is not meant to replace desktop virus scanners, and you should make no assumptions about our virus scanner checking your mail; you must have a desktop virus scanner to provide a second layer of security. Opus One virus scanning is a first-level type of scan, which means that we will try to block viruses from being delivered to your mailbox, but we only scan them with a single virus scanner.

The virus scanner we are using is from Sophos. We update signatures, if needed, on an hourly basis.