Email may implement From<String>, but Option<Email> does not implement From<Option<String>> (as your title says). Email and Option<Email> are distinct types. Since you can't implement a foreign trait on a foreign type, just implmenting From<Option<String>> for Option<Email> is off the table, unfortunately. As an alternative, maybe you can add another layer of wrapping with a struct MaybeEmail(Option<Email>) and derive From<Option<String>> for that (maybe manually instead of using derive_more).
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