Received undelivery notificaon 3 days after the email was sent
To my surprise 3 days after an email was sent I received an undelivered message notification presented as follows:
This is the mail system at host mx1.mailbox.org.
I'm sorry to have to inform you that your message could not
be delivered to one or more recipients. It's attached below.
For further assistance, please send mail to postmaster.
If you do so, please include this problem report. You can
delete your own text from the attached returned message.
The mail system
<firstname.lastname@example.org>: : TLS is required, but was not offered by host
Why the tremendous delay? Why one has to wait 3 days later to receive an unsuccessful mail delivery notification?
This is not acceptable for anyone using email services, regardless of the priority.
Can someone explain this occurrence?