[3.0] Add additional fields to support better mail queueing#8804

jdarwood007 merged 3 commits intoSimpleMachines:release-3.0SimpleMachines/SMF:release-3.0from

jdarwood007:3.0/MailQueueExtensionjdarwood007/SMF:3.0/MailQueueExtensionCopy head branch name to clipboard