The hosting company I used to use was bought out and was recently merged with Blue Host. Within weeks almost all of the handful of businesses I host starting having issues where all of their emails were going straight to their recipients spam. Upon contacting Blue Host's tech support, I was that those businesses I was contacting them about used "spam words" and that "on server end the spam filters are correct and perfect; now you have get the it whitelisted on the receiver's end as, there are no issue on the server end, everything is fine and perfect."
No other help was given, nor would they promote the ticked up a level.