Comment by toast0

Find a host that cares about their reputation. It can be hard to know who responds to abuse reports, but if they mention it in their TOS that's a positive. Also, many hosts block outbound port 25 by default now; that's a positive sign as well.

The more effort you have to put in to use them to send mail, the more likely spammers don't use them, and the more likely their ip space has a positive or at least non-negative reputation for sending mail.