facebook: how to send private msg without getting stuck in the spam filter?

So If I am to contact a bunch of people in a group and market to them , the message gets stuck in a spam filter that most facebook users never check. Is there a way to get around that?

like if you follow someone ( if they have that option) will that make sure it gets to the inbox?

what about if you tag someone in a post in a group and let them know you sent them a msg. will facebook send a notification to that person who got tagged?