When I added some filter in Cpanel, It will created files ~/.filter and /etc/vfilters/domain.com
I don't know which one is the master.
I modified the file ~/.filter to
$header_date: is ""+++++++/dev/null
I cat /etc/vfilters/domain.com , the data didn't change.
Then I tried to add some filter in Cpanel and delete it.
I cat /etc/vfilters/domain.com again, the data now updated.
Well, I goto Cpanel / email / filter
Viola! It shows my filter setting.
I tried to test by sent the no-date email, and it did work!
I don't know what is +++++++
Maybe it is cpanel syntax.
Hope these help for someone.