His assessment on how “Big Mail Corps” accept mail is plain wrong from my experience. When I ran my own mail server, I had SPF, DKIM, rDNS and strict DMARC setup correctly, and got 10/10’s on mail-tester.com.
Admittedly my main problems were with people on Microsoft hosted emails. They seem to run some kind of IP address based blacklist-by-default operation. My emails to Hotmail/Outlook.com users would randomly get either rejected or go straight to spam.
I went through countless online forms, Twitter conversations with clueless CSR’s who kept asking me what Outlook client settings I was using, and finding random people on LinkedIn I could message.
In the end the solution that seemed to work was to reach out separately to everyone I was sending an email to on Hotmail/Outlook.com and getting them to explicitly mark my email as not spam. After a while it seemed to take and stop rejecting/marking my emails.
I run my own, but from time to time large blocks of IP space on Digital Ocean seems to get put into some blacklist.
My solution was to use a fallback delivery through SendGrid and their free tier (happens rare enough, and my volume is low).
Postfix handles this nicely for me.
Admittedly my main problems were with people on Microsoft hosted emails. They seem to run some kind of IP address based blacklist-by-default operation. My emails to Hotmail/Outlook.com users would randomly get either rejected or go straight to spam.
I went through countless online forms, Twitter conversations with clueless CSR’s who kept asking me what Outlook client settings I was using, and finding random people on LinkedIn I could message.
In the end the solution that seemed to work was to reach out separately to everyone I was sending an email to on Hotmail/Outlook.com and getting them to explicitly mark my email as not spam. After a while it seemed to take and stop rejecting/marking my emails.