In the hope of streamlining account creation e-mail delivery and mailing list moderations, I have deployed SPF and DKIM over the weekend for e-mails coming out of @jenkins-ci.org, which includes account appliations, Confluence, and JIRA.
I've also used this opportunity to switch back the sender of JIRA notifications to noreply@jenkins-ci.org. It was originally this way, then changed to jenkinsci-no-reply@googlegroups.com when someone complained (on what ground...