I have hundreds of domain names, and my registrar (Gandi) recently started shutting down my email inboxes. A few domains utilize Zoho's email for custom domains, but I was wondering if anyone else has suggestions.
I use Sendgrid <<a href="https://sendgrid.com" rel="nofollow noreferrer">https://sendgrid.com</a>> with an inbound parse webhook which delivers the emails via LMTP to the inboxes and Dovecot <<a href="https://dovecot.org" rel="nofollow noreferrer">https://dovecot.org</a>> for reading. If you're sending less than 100 emails/day it's free. It's rock-solid and I've been using it for years without any issues at all. I can highly recommend it. Once you've set it up for one domain, adding more is trivial.
Are you just doing some sort of low-volume "owner@$Domain_Name.$TLD" account for each domain, or do you have a bunch of accounts and/or serious mail volume at many of them?