What is the best practice for contacts that are considered idle?
We have a number of contacts who gave once 10+ years ago but never since. We'd like to clean things up so that we don't waste resources chasing these old and idle contacts. Is there a best method for designating them? For example:
We can create a group, but then we need to remember to exclude that group in future mailings.
We can delete them, but that loses the data about their contributions from years back.
We could flag them as "do not mail" but that's usually only for people who have opted out.
How are other groups addressing this?