BB Bold 9700 :: Unidentified Email Clock Icon?

About 5% of the time when I send an email, ithe message does not get sent immediately but shows a clock icon where there would be a check mark if it had been sent. I don't find any documentation on what the clock icon is supposed to mean. Any message that exhibits the clock just sits and does not get sent until I manually select "Resend". On my old 8800, occasionally if the service could not be contacted or was busy a message would hang around until the service became available and it would be sent automatically. In the current case, no matter how long I wait (days) it never gets sent automatically.