4.35 Does LISTSERV support SPF/DomainKeys/DKIM/DMARC?
It's complicated.
LISTSERV does support SPF, if you have configured SPF support for your domain in DNS. There is no specific LISTSERV setup required for SPF, and if you have configured SPF correctly in DNS, it should work.
Until LISTSERV 16.0-2017a, Yahoo! DomainKeys was supported. However, DomainKeys is obsolete and in LISTSERV 16.0-2017a and following, DomainKeys support has been replaced with DKIM (DomainKeys Identified Mail) support.
For most LISTSERV sites that were already running with DomainKeys support, the change is transparent and requires no adjustment of your current LISTSERV settings. However, prior to upgrading to LISTSERV 16.0-2017a or later from an earlier version, sites running with DomainKeys support should take the opportunity to review their key pair, as key lengths which were sufficient for DomainKeys may be too short for DKIM. Per RFC 6376 "DomainKeys Identified Mail (DKIM) Signatures", Section 3.3.3, "Signers MUST use RSA keys of at least 1024 bits for long-lived keys", whereas many DomainKeys sites may be using keys of 512 or 768 bits.
LISTSERV also supports DMARC, if you have configured DMARC support for your domain into DNS. Note that DMARC is an "umbrella" protocol which requires that you have also configured SPF and DKIM, and that you have MX and PTR records in DNS for your LISTSERV server.