I have a client who recently has seen a huge increase in spam delivered to their mailboxes. It's not the usual Russian bride / Viagra junk you see on a day to day basis. Instead the content is almost relevant. Emails from Bloomberg, articles regarding Gaza etc. What gives it away is that the senders address are not what you would expect to see if they were valid senders.
Now this client has recently switched ISP and they are adamant that the increase in spam has occurred since switching ISP. My question is that can switching ISP providers see an increase / decrease in spam activity?
Client is running SBS 2008 with Sophos endpoint protection. I have increased the Spam filter setting in Sophos Puremesssge however it makes no difference as the emails are seen as valid and keep on arriving.