Filter for Contacts not having a certain Activity

Sven Amann_76110

We often want to find contacts that do not have a certain activity, e.g., people that we've send event registration details, but not the event followup. Currently, this is not possible, due to two limitations:

1. I cannot search for the absence of an activity, so for "contacts with no activity of type follow-up". I can only search for "contacts with activity of type is not follow-up", which is worthless, because that's all contacts with any activity of another type.
2. I cannot define multiple criteria on the same activity, so "contacts with an activity of type follow-up and with title 'my event'". I can only search for these criteria independently, so "contacts with an activity of type follow-up and an activity with title 'my event'". To different activities, each matching one of the criteria, would satisfy this.