Apart from the mime.mailcap.path option, you can configure if mailcap support should be disabled. The default being that it is enabled. To disable it just put:
set mime.mailcap.enable = 0
It is also possible to control whether ELinks should ask you before opening a file. The option is a boolean and can be set like this:
set mime.mailcap.ask = 1
if you would like to be asked before opening a file.