I have had the exact opposite experience, I used mail in a box and set it up on digital ocean on a 5$ droplet.
Have not had any spam or blacklisting issues and it was super easy to setup.
Have not had any spam or blacklisting issues and it was super easy to setup.
That happens even if you send from @gmail to @gmail. Well, it happened to me not long ago.
But I've mostly been using lesser known email providers and I haven't noticed any problems.
The nice thing if you control your domain is to be able to create unique email aliases, which is a way to cut spam to zero. A company starts spamming or leaks your email address, just delete the alias.