I have a forum with 35,000 from as far back as 2008. I'd like to send a mass email to let all of them know about the new update, but I'm not sure the best way to go about making this announcement. Is this something XenForo can do with built-in or add-on functionality? Do I need to use a mailing service such as mailchimp? What do you guys use to format the emails/newsletters?