Adds addresses to your autoBccExcludedEmails list, so messages to them are never auto BCC'd. Send one address as email or several as emails; when emails is an array, email is ignored.

Each address gets its own result. Addresses that do not look like an email address are skipped with success: false, and the call still returns 200. An address already on the list is not added twice. Addresses are stored as sent, without trimming or lowercasing.

To remove addresses, send the full list you want to keep as autoBccExcludedEmails to PATCH /userpreferences/me. That replaces the whole list, so an address another client adds between your read and your write is lost.