I did all of this when self hosting for a few years. It was mostly fine, but for a couple of undelivered emails. Those were just enough that I lost trust in the system and eventually stopped running my own email.
People mostly expect email to be fully reliable. It’s not, but that doesn’t stop people treating it like that. As a result, even if you only fail to deliver 1 in 1000 emails, that could have significant consequences. Gmail et. al have a high enough deliverability rate that most people can get away with treating it as reliable.
I’m not saying people shouldn’t self host, but I think they need to be very aware of how it will change their trust of email.
IMO, what needs to happen is for people to see the 1 in 1000 as a problem with Gmail et al. rather than a problem with someone hosting their own STMP server.
Generally speaking, people I know who self-host their email do not have problems. However, inevitably there is the 1 in 1000. IMO, unreached recipients using Gmail et al. are likely to see the problem as with the self-hosted sender, not their own third party email provider.
One idea is to have a backup for emergencies. That is, a Gmail user could have an alternative, self-hosted means of receiving email on port 587 or 2525. By default, this mail drop accepts mail from no one. When there's a 1 in 1000 problem, the recipient could add the sender to a list of acceptable senders, either temporaily or permanently. The sender can then use the alternative instead of Gmail.
To be honest, in the last 20 years or so of self-hosting emails, the most common failure points were
• Gmail marked an email as spam, but still delivered it. Easily cleared up, no hard feelings on either side.
• Someone else self-hosts some abysmally maintained Exchange 2003 setup that just about barely works with GMail and Office365, after the MSP irresponsible for it gets enough verbal beatings. Impossible to get to work.
Your right, but email is never fully reliable. How many times have you lost things into your gmail/outlook/etc's spam folder?
And with the amount of genuine spam being sent FROM GMAIL to my backup gmail address, it's unthinkable to actually check through the spam folder with any regularity.
People mostly expect email to be fully reliable. It’s not, but that doesn’t stop people treating it like that. As a result, even if you only fail to deliver 1 in 1000 emails, that could have significant consequences. Gmail et. al have a high enough deliverability rate that most people can get away with treating it as reliable.
I’m not saying people shouldn’t self host, but I think they need to be very aware of how it will change their trust of email.