Outlook In box shows (1) but no message listed. Why?

[Nancy 68]

Sometimes I get the audible sound that mail has been received, I even get a
brief view of the subject/senderat the foot of the screen
, inbox shows (1) but there is no mail listed. This only happens now and
again. At all other times the system seems to work OK. Any ideas anybody?

 

[Brian Tillman [MVP - Outlook]]

Sometimes I get the audible sound that mail has been received, I even get
a
brief view of the subject/senderat the foot of the screen
, inbox shows (1) but there is no mail listed. This only happens now and
again. At all other times the system seems to work OK. Any ideas
anybody?

Do you have rules or a mail scanner running?