Thank you for supplying the PING and TRACERT information as well as the account configuration information.

It does appear there is a security protocol inplace for bellsouth.net. This is very common and is not the cause of the intermittent delay.

When these messages sit in the Outbox unable to send, there can be multiple reasons this is happening. We have eliminated the SMTP server information being correct, the SMTP port being blocked or recipient server experiencing packet lose,

If your SMTP server is in house see if you can locate any traffic logs. This may shed some light on what is causing these delays.

Last possibility is how this user connects to the internet. If connected wirelesslly attempt to troubleshoot connectivity loss between the user and the SMTP server.