What if the recipient’s server is programmed not to send acknowledgements or receipts?
The Registered E-mail service uses standard SMTP protocol and a proprietary process to determine if a message was delivered; what level of delivery took place, or if there was a failure due to a bad address, the receiver’s network being down or their mailbox full. This is done fully independent of the receiver’s system being configured or not configured a certain way. Therefore, the opted “send no acknowledgement” has no impact on the Registered Receipt e-mail being automatically returned to the sender.
