This type of abuse happens frequently to many domain name owners, since spammers rarely use their own domain names in SPAM and viruses select addresses randomly from other people's address books.

Sometimes spammers just make up return addresses to put in their spam and it is a coincidence they this time they chose one that happens to belong to you. Sending an email that appears to have come FROM someone who did not send it is known as "forging email".

Anyone with Outlook or any other email program can forge whatever address they want in the FROM field of an email, regardless of whether they own the domain name in the address, regardless of whether they have permission to use it, and regardless of whether the domain name even exists or is valid. There is nothing that the rightful owner of a domain name can do to stop people from sending out email with an address in the FROM field using someone else's domain name.

There also is nothing that a webhost can do to stop or prevent spammers or virus mails from wrongfully claiming that your email address came FROM or was the sender of a piece of spam or email virus.

The most annoying part of having someone forge your email address in the in FROM field of their outgoing SPAM is that nondelivery and other bounce notifications will be returned to you because the undeliverable messages appears to come FROM your address.

There are a couple of ways to avoid receiving those. If the username part (left of the @ symbol) of the forged FROM address is not a mailbox that you set up in your Control Panel, then you are receiving the unwanted messages through your default address. To stop receiving these messages, you could set your default address to ":fail: no such address here" so that you will no longer receive mail addressed to non-existent addresses at @yourdomain.com. Or, if you want to keep your default account, but just want to disable incoming email for one particular address, you can create a forward in your Control Panel for the unwanted address and set it to forward to ":fail: no such address here" to bounce the email or ":blackhole:" to simply delete it.

If the forged email address is one that is important to you, that you need to receive email at, there is nothing that can be done short of using the email filters in your Control Panel to blacklist the FROM addresses in the undeliverable notices, such as postmaster@yourdomain.com. However, this is not recommended because messages FROM those type of addresses are often important and most of the time you will want to receive them.