Milter-greylist

Anyone notice that Linode’ s address space appears to have recently grown significantly?

I only get UGG Outlet and Sunglasses spam from their address space, which is why I notice.

Also… what is the consensus of reporting spam back to the originating ISP?

I used to do this faithfully, by attaching the original message in a new email back to the abuse/spam address listed on the ISP website. 
That way the ISP will have ALL the info needed to prove that it was spam and where it originated.

But Microsnot/Outlook in their infinite wisdom doesn’t allow attachments. 
So I used to forward the emails to them with a new subject line. Well… they then decided I was a spammer and started blocking all mail from my server!
I had to call them to get the block lifted, but I’m now on probation...

Most of the time I don’t get any response, so I wonder if reporting is a wasted effort.

Bill