When trying to send a new email using Mailenable webmail, the following error appears:
FreeTextBox has not been correctly installed. To install FreeTextBox either:
(1) add a reference to FtbWebResource.axd in web.config:
Handler for *.axd is missed
Go to handlers in IIS->handler mappings and add handler:AXD-ISAPI-2.0request path: *.axdexecutable:
Make sure that handler appears in IIS->webmail(mewebmail)->mewebmail
Additionally please check Mailenable article .