For anyone using a custom domain, or thinking about it, read this: https://dmarcly.com/blog/how-to-implement-dmarc-dkim-spf-to-stop-email-spoofing-phishing-the-definitive-guide
Without these records you're a lot more likely to go to spam, or get rejected outright. If you have questions about it, ask here or DM me and I'll be glad to help.