This is sieve-connect. A client for the ManageSieve protocol, as specifed in RFC 5804. This is not yet fully compatible with RFC 5804, but is moving towards that from the timsieved baseline; some issues to be worked on are documented in the "TODO" file. sieve-connect speaks ManageSieve and supports TLS for connection privacy and also authentication if using client certificates. sieve-connect will use SASL authentication; SASL integrity layers are not supported, use TLS instead. GSSAPI-based authentication should generally work, provided that client and server can use a common underlaying protocol. If it doesn't work for you, please report the issue. sieve-connect is designed to be both a tool which can be invoked from scripts and also a decent interactive client. It should also be a drop-in replacement for "sieveshell", as supplied with Cyrus IMAP.
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.