nostr:npub13ffffa9gzjxjgtk02vy0thqk6wuhzayxge2rzy4ur4y852w0hxvs8gnjfq Well I've not done exactly what you have so I maybe wrong here. Using say Mailchimp or even self-hosted solutions you end up using your own email address and verify it to your domain. So unless you self-host email, your email provider is responsible for looking after delivery problems, domain blocklists, spam, etc.