It's addressed in the article:
> The elephant in the room is real-world deliverability. With self-hosting you risk not receiving mail or someone missing your mail. I accept this for my personal projects, but you may not. Keep this in mind.
> The elephant in the room is real-world deliverability. With self-hosting you risk not receiving mail or someone missing your mail. I accept this for my personal projects, but you may not. Keep this in mind.