The spam filtering companies do make mistakes sometimes. Sometimes someone is sending out legitimate mail but it's a new IP sending a bunch of mail and they err

The spam filtering companies do make mistakes sometimes. Sometimes someone is sending out legitimate mail but it's a new IP sending a bunch of mail and they err on the side of caution. Or sometimes your IP will just get caught when a spam company decides to spam flag an entire block of IPs. I think if OP keeps at it, they will find that it's not worth the hassle and for a very reasonable amount of money they could have just had a personal email server where someone else deals with the headaches. Of course, again, I work for a hosting company so I may be biased here but I'd probably be saying the same thing even if I didn't.