B.R.
I get emails like that fairly often, but don't believe they are as a result of Mamasource. In my case, my email provider puts them into the SPAM file, and I only see them when I empty that file each day. I never open them, but simply delete them. If your server has a "report Spam" function do that. Otherwise simply deleting them and ignoring them is about the only advice I can give you. Whenever you open such emails you not only have a chance to encourage more of the same, but you could be putting yourself at risk of a computer virus.