But there are even people that still self host email server (have a look in the selfhosted subreddit for example).
IP reputation is a thing, for sure, but I don't feel that it's been brought up by the big corp wickedly, it's a good way to prevent spam to arrive to the server.
There are thousands of email providers in the world that are not Google, Amazon, Microsoft or some other big corp. This means that is possible.
Is it difficult? For me for sure!!! But I think that the rising difficulty has been a result of this fields over the years.
Just my 2 cents.
With DKIM and SPF, I've had zero problems in the last 15 years of selfhosting, most recently with Mailcow Docker on a residential IP. I don't even have a reverse PTR to my mailserver hostname, just a PTR provided by the ISP that can be resolved.
I've added a few fresh, un-reputed domains to the server and had no issues.
I think many people's problems with running email servers are self-inflicted. I remember even before there were things like blacklists, etc with large providers, many people had problems keeping mailservers running. It's just not an easy task for a variety of reasons completely unassociated with the mega's blacklisting you. I've been running mailservers at various scales for 20+ years so maybe it's just second nature to me now.
ip-reputation is also important.
Mailgun, an email service for mass mailing, is doing an „ip-warmup“ if you choose a dedicated ip. So, if you are self-hosting with dynamic-ip, i think you would have a very very low ip-reputation.
No idea! I don't run my own mail server.
But if you read a bit up here, there's a guy who runs his own mail server(s) since years.
But the selfhosted world seems to be full (well...not so full) of people that self host their mail server.
@loppwn@peregus not having PTR, DKIM, SPF, DMARC correctly setup is a killer, but there are great solutions for this nowadays, both #cloudron and #Yunohost take care of that part pretty well