[Cu3PO42]

It absolutely does not. I tried setting up mail on my own server and by all accounts I did everything right. Mail-Tester and similar services found no issues, I had all the optional records including DKIM, SPF, etc. and yet I couldn't rely on my mail going through.

Microsoft (Outlook.com) was particularly bad: mails were silently dropped without notice to me or the recipient even when I was replying to a mail they sent. I tried adding my e-mail address on my own servers to the trusted senders list on a MS account of my own and even then not all mail would go through.

Gmail ocasionally put me in spam but at least always delivered my messages.

At that point I gave up since I consider email to be too essential to be flaky and paid for Migadu. I have been very happy with their service and appreciate their pricing strategy (charging for number of mails sent, not the number of domains or mailboxes added). That said, I still dislike paying for hosting that I had sufficient capacity for on my own servers.