I've run into countless problems because of my messages being marked as spam. The worse is that now it as become socially acceptable to ghost people, I never know who ghosted me, the mail server or the person! I've run into "I ignore your email, get the hint" a few times when thinking I was marked as spam and tried to contact people through other means.

Right now, when you send an email, you don't know if it was received or not and if the lack of answer is a conscious decision or because of filtering.

Do you remember the bad old days of spam?

Left unchecked I think it might have destroyed the e-mail ecosystem entirely.

Regarding the block vs reject, that unfortunately gives a big tip to the people whose working hours are spent trying to defeat three blocks and send you more spam.

There is not reason at all to suspect that a message from a small server with proper SPF and DKIM that has never sent spam (for real or spoofed, see SPF), is spam. The other half is from small servers that sprung over night and have no reputation.

Half of the spam I receive is from google/outlook/amazon. They don't block each other, do they?

Thankfully all my customers have been super understanding and were kind to take the disputes back once they were able to locate the emails in the Spam folder. Also I finally decided to just use a "reputed" smtp server to fix my problems (feels like extortion but what can you do).

I've written this before, but it's so sad that something so important and vital like email is so broken and we are the mercy of corps like Google/Apple/Microsoft and everyone has their own secret policy.