Just a quick add: even for my self hosted services, I configure Postfix with Mailgun for SMTP relay for alerts and whatnot just to ensure delivery to my external mail provider.

Edit: a few words for clarity

Just passing along what I’ve read many times: that self hosting email can be difficult. Particularly sending, because the large providers tend to treat email from less known sources with more skepticism (such as by marking as spam), even with properly configured SPF and DKIM.

And if your server is down, you may miss any incoming mail for the duration. I don’t know if other providers would try resending after a period of time if the receiver is unreachable, but I doubt it (just an educated guess).

I love self hosting services but email is something I’ve decided not to touch with a ten foot pole.

+1 for Fastmail.

I’ve been using it for about 3 years. I’m on the Standard plan (middle tier). It’s $4.20/mo. per user when prepaying for 3 years and ranges up to $5.40/mo. for monthly billing.

Not sure if there’s a (practical) limit on domains or aliases, but I have 7 domains and a few aliases plus a wildcard. Includes 30GB of storage per user.