Iam not sure whether the transmit dialog box can display messages related to BAPI. But we can modify the transmit configuration definitions to handle network issues,in the sense if there is no network we can display custom messages to the user when he tries to sync using that network connection type.
Please find the below screen shot where by default the connection checkbox is unchecked.Write a custom message in 'Connect Prompt'.
If the user is trying to connect using network transmit configurations,if the connection cannot be established,the custom message will be displayed.
Check in ATE.
Hope this may be helpful...
Regards,
Sravanthi Polu