This year I submitted a paper to a conference that used ConfDriver of TU Wien. From the time of submission, I started receiving a lot of CFPs from conferences that also use ConfDriver.
All the conferences seem solid, and the emails are from researchers of well-known institutions. However, I find it really annoying, because they are completely unrelated to my research area, and sometime unrelated to Computer Science.
There is no option to "unsubscribe" to these kinds of CFPs, and there is nothing in common to make a filter in email client.
By the way, I find ConfDriver much worse than EasyChair, and it even doesn't notify the co-authors when making (or updating) a submission.
I understand that some people from TU Wien may be upset with this question. But what this ConfDriver is doing is really spam, and it is really annoying. Unlike spams from junk conferences, this kind of spam is much more difficult to block, since the emails are from well-known institutions, e.g. MIT etc.