Or you could try Certified Mail from TMail21.
<a href="https:&#x2F;&#x2F;tmail21.com&#x2F;why-tmail&#x2F;mission-critical-processes&#x2F;" rel="nofollow">https:&#x2F;&#x2F;tmail21.com&#x2F;why-tmail&#x2F;mission-critical-processes&#x2F;</a><p>Mail is certified, identity is non-spoofable, delivery is guaranteed and unlike regular postal certified mail, even the content is certified. In other words it has all the guarantees of normal business transactions like in ERP&#x27;s like SAP and Oracle.