Answer
By default Gordano Software uses non-blocking TCP/IP sockets, this appears to cause problems for those using Internet Explorer with GMS Webmail over SSL.
The solution is to set the services to use blocking sockets instead. To do this go to the Support > System Variables page, select the variable BlockingIO from the scrollable list, enter a value of 64 and click on the Update button. Once the WWW service is stopped and restarted the problem attaching files to messages using SSL should no longer exist.
See also
How do I edit system variables?
See Also:
Keywords:SSL, GLWebMail, Attachments, Files, Messages