Hi! So I have probably like 3-4 email lists from things throughout the years from event and random newsletters I've started and never comleted... also have a substack with 800 subs that I never touched. How much of a bad idea is it to throw those people onto my current active newsletter?
In worst case scenario, very very bad.
You could check the list before importing into beehiiv on external platforms to clean it up. And then pray that the remaining clean list don't mark you spam