Spam Email Notifications From PlusNet

[#1]

I've just started to receive emails purporting to come from PlusNet and addressed to some gibberish at my plusNet domain.
They start:

Quote

Dear Plusnet Customer, You are receiving this mail because you have an active virus-scanning service, and either a banned file extension or an email containing a virus has been sent to your address.

and end:

Quote

It should be possible to reply to this mail to retrieve your email, as long as your email application includes this entire message in the reply. Kind Regards, Customer Support.

The body of the text requests I send an email too unquarantine@quarantine.plus.com to retrieve the email. Obviously I have no intention of doing this!
What concerns me is the fact that the spammer knows my address is with plusNet. Has there been a further security beach?
Regards.

[#2]

Just looked into the Email settings and see the Spam settings.
It's been a long while since I've entered this section of the portal.
The fact that the email address to unquarantine is at unquarantine@quarantineus.plus.com should have alerted me to the fact it could be genuine. Apolgies for jumping to conclusions.
How long have these new (to me anyway) settings in the email section been there? Have they something  to do with when I went on the Postini trial in January?
But why have I only just noticed these unquarantine emails being received?
Regards
Edit;
BTW the Quarantine option is currently (and has been) unset for all my domains

[#3]

Very Recent, i.e. this month, lots of people moaning that they haven't had a report yet, you are the first person I have seen that has had one 

[#4]

Actually, I have had three.
I really should pay attention, though.
Seems we're talking anti-virus protection and not spam filtering and this option is On for all domains.
Apologies again.

[#5]

You've had a report because your mail contained a file with a banned extension (.exe etc.) or contained an actual virus file. 
This is because you've activated (at some time in the past) virus scanning of your e-mails. This is separate from the Postini quarantining (especially as you've not turned on the quarantining of your spam messages).
It could be a virus or it could be someone you know trying to send a legitimate file (with a banned extension!).  If it's the latter, you'd need to request the release of the email from the virus scan quarantine (as described in the mail you got) as opposed to Postini's spam quarantine (which requires you to log onto the Postini web site.)
Spam filtering by Postini and virus scanning by PN are two different things!
Edit: ....as you've noticed  :)(I was typing this as you were replying and have just read your post!)
Edit 2: spelling errors corrected

[#6]

Thanks Paul03
I assume that the Anti-virus filtering must have been set to on as default. I don't ever remember actually turning it on.

[#7]

The anti-virus thing can be useful; occasionally it also blocks phishing attempts... although it lets through more than it does block!

[#8]

Hi Mav, if you're happy that the email you got was genuine after all, I wonder if you should ask the moderators to close off this thread? Otherwise it might attract posts that belong in other spam threads and cause confusion.

[#9]

Fair enough - if one of the mods can lock this thread, then, please
Thanks for all the advice!

[#10]

The virus notifications were broken when we first introduced Postini. Viruses were still being quarantined but there was no accompanying email. I thought this had been fixed TBH before the recent changes but looks like I could have been wrong.
If you use Postini Quarantine then you'll notice you have a separate tab for viruses that are caught.
There's a support pages for the virus notification stuff here.

[#11]

Quote from: Mav

Fair enough - if one of the mods can lock this thread, then, please Thanks for all the advice!

Lockinated at the request of the OP