Over the last couple of months, I've seen a significant increase in failed emails on both macOS and iOS. The email will fail and land in the inbox. Sometimes just telling it send again will make it go through. I've deleted and reentered my email account. I'm using TLS with user name and password on both incoming and outgoing. Sometimes the reply from your mail servers is that the message is spam. It's not, so your settings are too strict, but many times it's not a false positive on spam. Please advise.