Bug#991204: exim4-daemon-heavy: Please add SPF support

[Wouter Verhelst]

Package: exim4-daemon-heavy
Version: 4.94.2-6
Followup-For: Bug #528344

Perhaps important to note is that both DMARC and (currently still
experimental, but...) ARC both depend on the builtin SPF support. While
the SPF "support" by calling an external binary may work for SPF checks
at a cost of a fork per ACL test (i.e., some performance penalty), this
is not the case for the extra functionality that depends on the builtin
SPF support, such as sending out DMARC validation reports, and adding
ARC headers (to mitigate the issues with forwarding emails).

Please seriously consider this wishlist item for bookworm already...