Is this a scam - mail delivery failures

[Lucifer Box]

Or someone's faked the reply-to field in a shed load of spam they've sent out.

This is the most likely, especially if you own your own domain. In this case you'll find the reply to field in the original email sent out is ibblybobblyboo@yourdomain.com and your catch all has picked it up when it bounced back from a non-existent address. Not much you can do other than turn off your catch all, but it will subside in a few days' time.

[ladymuck]

Or someone's faked the reply-to field in a shed load of spam they've sent out.

[Clippy]

Someone with your address in their Outlook address book has been hit with a virus which tries to propogate further by sending itself to all email addresses in the users Outlook address book and spoofing the 'sent from' address to yours.

Obviously this means that any bounce backs end up in your Inbox.

Don't sweat it - just make sure your AV is up to date.

[Gonzo]

Your machine has been taken over as a Zombie is always a possibility.

[DimPrawn]

It means you are a sleep spammer. In the night without realising it you are sending out 1000's of emails about Viagra and penis extensions.

See your doctor asap.

HTH

[Moose423956]

I keep getting mail delivery failures for addresses that I've never sent an email to. Is this some sort of scam, or just a balls-up by the ISP?

For example:

This Message was undeliverable due to the following reason:

Each of the following recipients was rejected by a remote mail server.
The reasons given by the server are included to help you determine why
each recipient was rejected.

Recipient: <vickielg79@msn.com>
Reason: Requested action not taken: mailbox unavailable


Please reply to <Postmaster@ispmail.ntl.com>
if you feel this message to be in error.