I used to do this. What finally killed it wasn't reputation, it was the fact that I needed 100% uptime or risk losing messages, getting my address blacklisted, etc. Email is supposed to be resilient to down time (retries, trying each MX record, etc.) but I found that large mail providers tend to just bounce and walk away.
Worse, GitHub (back in 2016 and 2018) would mark a recipient as "unavailable" after a single bounce, refusing to send any more notifications to that address. They since improved the situation and their support was actually very helpful and responsive here, but it's pretty clear that modern SMTP senders have an expectation that recipients will be "always online" that didn't exist when the protocol was invented.
Worse, GitHub (back in 2016 and 2018) would mark a recipient as "unavailable" after a single bounce, refusing to send any more notifications to that address. They since improved the situation and their support was actually very helpful and responsive here, but it's pretty clear that modern SMTP senders have an expectation that recipients will be "always online" that didn't exist when the protocol was invented.