A mask modifier behaves like an ip4 mechanism would if SPF had
included a negation. For instance:
m=-65/8
would be
-ip4:!65/8 # NOTE - ficticious syntax, '!' not in SPF spec
Since it is a modifier, it must also be possible to ignore it without
changing the result.
I don't know if Radu intended this, but the mask modifier should also be
position dependent. If supported by a checker, it should be evaluated
when encountered. This makes it the responsibility of the SPF compiler or
human record designer to place the modifier appropriately (e.g. after A
and MX mechanisms). This simplifies checking software.
--
Stuart D. Gathman <stuart(_at_)bmsi(_dot_)com>
Business Management Systems Inc. Phone: 703 591-0911 Fax: 703 591-6154
"Confutatis maledictis, flamis acribus addictis" - background song for
a Microsoft sponsored "Where do you want to go from here?" commercial.