When executing as non-root user this command: smbget --username="axel" --password="foo" --outputfile="/myfile.txt" smb://magina/temp/test.txt

The result file "myfile.txt" is not save in /myfile.txt but in the current directory. It seems that the leading slash is skipped by the smbget command.

Another example :
axel2@axel-asus$ smbget --username="axel" --password="foo" --outputfile="/tmp/myfile.txt" smb://magina/temp/test.txt
Can't open tmp/myfile.txt: No such file or directory
axel2@axel-asus$