Oddly enough I do not have these problems after self-hosting for close to 27 years now (i.e. from before spam became a problem). I hardly ever get any spam and my messages seem to arrive where they need to be even when that destination lies in Microsoft- or Google-land. I have the usual assortment of DKIM/SPF configured for my domain, I send mail through a smart host operated by my IAP (at no extra charge) but for the rest I do not do anything special. Am I the exception to the rule, am I just lucky that my IAP's smart host has not been blacklisted by the likes of Microsoft and Google or is the perception of self-hosting mail to be fraught with problems erroneous? I suspect the latter to be true, self-hosting is neither difficult nor bound to fail just as long as a) you have some good spam filters (easy), b) your MTA is set up with the correct SPF and DKIM records (also easy) and c) you send outgoing mail through a smart host (easy to configure once you've found one).
