Has Something Changed? Lots of 552 rejects (spam/virus reason)

[#1]

Hi,
Did something change at PlusNet at the end of last week? I've started getting lots of 552 mail rejects citing spam/virus as the reason.
Now, as it happens they probably are spam, so in a sense it's understandable, but it's only started happening at the end of last week and is already becoming a bit of a pain because it's then causing a mail-loop as the reject email appends the offending email to the end of it and it then spirals out of control !!
Thanks, David.

[#2]

Have you looked through the thread -  "Cloudmark anti-spam migrations October 2011"

[#3]

OK, just found the blog post about Cloudmark, which is no doubt the cause.
I thought PlusNet picked-up mail loops automatically, but I guess not; I'll have to add my own headers I guess.
Thanks, David.

[#4]

Thanks Purleigh, I just found that as well. Obviously that's the cause.

[#5]

Quote from: daveyb

Did something change at PlusNet at the end of last week? I've started getting lots of 552 mail rejects citing spam/virus as the reason.

Are you smarthosting mail through our relays using your own mail server or something like that David?