Would you recommend hosting for that use case?
I know some folks have concerns with the privacy of that(1), and really want to run their own SMTP. If that's the case, Mail In A Box can do the job, or you can go with a pure SMTP solution like https://github.com/ix-ai/smtp (not endorsing it -- it's just been on my radar) or a roll-your-own Postfix/Exim solution. The latter requires almost zero resources after it's set up; slap it on a $20/year VM and you're done.
1. Chasing privacy with email is a chimera. If you really want private communications, email is not the tool.
I prefer something like Brevo, which has smaller jumps per tier or even something like MXRoute for $49 per year (limit of 300 emails/hour)
Edit: Completely forgot about ZeptoMail by Zoho - incredibly good value service.
What got me interested is their integration with traefik. It just worked. Not without 9 hours of finding out the right proxy settings, but know I'm attached to it like to IKEA furniture.
On a more serious note, they showed an example of properly proxying a imap/smtp SSL connection. If you asked me before integrating it, I'd have thought it might be impossible, since SMTP has some STARTTLS negotation baked into protocol.
I only knew how to proxy SSL in HTTP and never knew that bare TCP can be used to PROXY and terminate tls as well.
* Every thread that mentions hosting your own email brings out the it's-pointless-do-do-your-own-mail zealots; ignore them. If you're interested in trying it, try it.
* The only deliverability issues I ever had were with ATT networks because they don't use modern TLS; that was fixable. Mail to Google? Goes through, doesn't go into spam. Mail to Microsoft? Ditto. And this is on a Digital Ocean VM, which isn't the most reputable IP pool in the world.
* MIAB will happily be your full-fledged authoritative DNS server. Although I've since migrated to separating DNS from mail hosting, it was very convenient for a long time.
* Setup is dirt simple. And you get MTA-STS as well as DANE/DNSSEC right out of the box.
* The backup function worked without issue the one time I needed it. I'm sufficiently paranoid that I also do regular snapshots of the whole VM.
* There's a fork, Power Mail In A Box, that updates the UI, adds the ability to plug in relayhost settings, and does a few other nice things. It hasn't been updated in about a year, but was similarly solid.
My only quibble with MIAB, and the reason I migrated to Mailcow recently, is that I wanted to easily set up per-domain relay settings from the UI.