Not necessarily true. A well configured mail server should be just fine. I personally use https://mailinabox.email/ to handle configuration for me and that works great.
If you're concerned about deliverability, you can also use a service like mail-tester.com [1], which receives a message you send and analyzes it for a wide variety of potential problems. I've found it to be a good guide.
[1] https://www.mail-tester.com/