While scheduling new jobs, you can select the option ''Compress report'' if you want the report to be compressed in the email sent. Normally, this option is not selected by default. Now you can set this setting to be selected by default (in /fileserver/etc/main/main.cf):
<scheduler> <email> <defaultcompression>true</defaultcompression> </email> </scheduler>
If you set this to true, ''Report compression'' will be automatically selected when scheduling new jobs. Defaults to false.