It's always been best to rely on a third party to send your email. Having to deal with IP blacklists is a pain in the arse! I will never go back to managing my own email servers that send email. Customers get hacked, their websites get hacked, websites can accidentally send bulk emails because of getting hacked and/or improper pre-spam settings on forms -- there's just too much to worry about.
Having said that, I am testing out (have been for months) using the Smart Host option that Enhance provides via Amazon SES. I have a dedicated Email server that receives email and sends via Amazon SES. Only for my domain names.
For me, this is working out great. My personal, business, and help-desk emails are not going into the receivers junk folders. Even my transactional emails are getting into the Inbox.
I've had to install my own sieve filters on the email server so I can filter incoming emails (the downside is when Enhance updates the mail side of things, I have to redo the install, configure, etc), but it's working flawlessly. I do get the occasional spam email (perhaps 2-4 a day), but after verifying the headers it's really legitimate spam emails. I keep marking them as Junk so rspamd can 'learn'. I'm not really sure how efficient that is. Because I installed the sieve filters (including the Roundcube plugin), I can manage certain keywords 😉 that I just either mark for spam, or mark for delete.
For me, this is where large third party providers come in and help with receiving emails... by completely mitigating spam for it's users. A small amount of their users will receive a spam email, mark it as spam, and then the remainder of their users no longer receive the same email.
I know of Cloudflare's incoming anti-spam product, but it won't allow me to send from the same domain however, I do like the idea of sending the emails to a larger provider who can adequately scan emails prior to receiving them.