Gunnar Hjalmarsson wrote:
I believe there are two important reasons to bother with SPF records:
1) You give a small contribution to the 'right side' in the war
against spammers and other contemptible abusers, to the benefit of
the vast majority of serious netizens.
2) You reduce the risk that your domain gets hijacked and used by
spammers in forged sender addresses.
Correction, I forgot the third reason:
3) You increase the chances that your messages get through when
receiving mail servers use SPF as one criterion for filtering spam.
At the same time, there is no reason to hope that an SPF record will
make a big difference as regards the volume of received spam (except for
bounces due to domain hijacking, that is).
/ Gunnar