Hello,
We had similar issuue. We opened a SR and we disabled messaging following the suggestion of Avaya engineer :
"Messaging Icon can be removed from workplace, and this be controlled using 46xxsettings file.
Option - SET ENABLE_IPO_PORTAL_MESSAGING 1 (enables IPO messaging)
SET ENABLE_IPO_PORTAL_MESSAGING 0 ( disables )
When you disable IPO Portal Messaging icon will become invisible." .
When you change 46xxsettings , you have to reset to default Workplace Application & program it again.
Best regards.