It is because sendmail on the mail server has been set up differently than before. Mail is now delivered via a mail queue, so delivery is not always instantaneous. It said that the message was accepted for delivery. The mail was checked e-mail again, still none of the recently sent messages were there. In the mail server's previous incarnation, the load limit was reached on a fairly regular basis.
Child process says message accepted for delivery, ends the connection, and dies.
In addition, if a message took too long to be delivered, Eudora timed out and complained. Grandchild finishes anywhere from right away to a long time. Once the grandchild finishes, there are two different outcomes. Eudora becomes impatient and reports that the delivery failed. Grandchild finally finishes sending the message.