SPF (and related systems) present a challenge to forwarders, since the envelope sender address might be seen by the destination as a forgery by the forwarding host. Forwarding services must rewrite the envelope sender address, while encapsulating the original sender and preventing relay attacks by spammers. The Sender Rewriting Scheme, or SRS, provides a standard for this rewriting which makes forwarding compatible with these address verification schemes, preserves bounce functionality and is not vulnerable to attacks by spammers.
Binary packages can be installed with the high-level tool pkgin (which can be installed with pkg_add) or pkg_add(1) (installed by default). The NetBSD packages collection is also designed to permit easy installation from source.
The pkg_admin audit command locates any installed package which has been mentioned in security advisories as having vulnerabilities.
Please note the vulnerabilities database might not be fully accurate, and not every bug is exploitable with every configuration.
Problem reports, updates or suggestions for this package should be reported with send-pr.