This has become bad enough that operators of personal mail servers are put into no-win situations and generally give up.
Either we can concede defeat and relay personal correspondence email through a commercial service or we can just accept that some recipients will not receive our emails.
I've adopted the latter stance because I don't operate a business that uses my personal mail server and therefore have the luxury of not caring a whole lot. My stance is that if a recipient is using an email service that blocks me for no good reason, they don't want to receive my email. They can complain to their service provider if they choose to. In a few cases, I've asked them to complain to their service provider and have seen some minor corrective action. But that's pretty rare.
Either we can concede defeat and relay personal correspondence email through a commercial service or we can just accept that some recipients will not receive our emails.
I've adopted the latter stance because I don't operate a business that uses my personal mail server and therefore have the luxury of not caring a whole lot. My stance is that if a recipient is using an email service that blocks me for no good reason, they don't want to receive my email. They can complain to their service provider if they choose to. In a few cases, I've asked them to complain to their service provider and have seen some minor corrective action. But that's pretty rare.