jira.mariadb.org outbound mail IP 34.70.47.92 is listed on Spamhaus CSS, so notifications get quarantined

Jira notification emails from jira@mariadb.org are sent from 34.70.47.92 (92.47.70.34.bc.googleusercontent.com, included in the mariadb.org SPF record). This IP is currently listed on Spamhaus ZEN via the CSS list (return code 127.0.0.3, see https://check.spamhaus.org/query/ip/34.70.47.92). Receivers that check ZEN quarantine or reject these notifications. In my case it's the addy.io forwarding service, which quarantines them with the message "The sending IP address 34.70.47.92 is listed on Spamhaus ZEN". Please request delisting via the Spamhaus page, or send Jira mail through one of the relays already in your SPF record (Google or SendGrid), which would avoid shared GCP IP reputation problems.