as far as I know, Nokiai blocked all *.sis files for sending.
I don't think you have the possibilty to create a unprotected sis file because the protection is founded on the *.sis ending.
I read somewhere that its possible to rename the file.sis in something like file.xxx , send it, and rename it back.
basically you could rename the ending to sis_ for example and get it sent. Then the other problem is that the application manager names the installation info with the same ending, so it will not appear in intalled list and so for can't be directly uninstalled.
so, in case you do use the ending method for sending, then you should also check in first run aftern installation that if the installation infor file has wrong ending, you would change it to normal sis ending, so it would then appear in installed list and could be uninstallaed as well.
Thanks Yucca for your answer. It seems to be working.
However how safe this method of renaming files in installation directory is? For example how often the system installation directory changes or how long ".sis_" files can be installed with Series 60 phones?
The Nokia's assumption that all SIS -files are protected is failed. At least they should give us a way to make unprotected SIS -files.
the problem is basically that they try to mtackle with software piracy, so it is good way to prevent SIS sending from the phone.
The implementation was not really good thou, and so for the workaround works. Basically in symbian the file types should be checked by cjecking the internal structure of the file not by ending, so installation files when run will always opened in installed, what ever they name or ending is.
Then the copy protection was made sloppily and is only checking the file ending. Similarly the application manager is just cheking the file ending and showing the files that have sis ending in its list.
So basically the method decriped earlier works ok, and can be considered safe as well.