4D today announced that it is shipping 4D Mail 5.2.4, a free update to all 4D Mail users, now with a significantly updated 4D WebMail Pro, new administrative options, and more. Version 5.2.4 now offers several new administrative options, including per-user storage limits with customizable warning messages. 4D Mail reliability improvements include updated compatibility with mail clients and significantly improved DNS handling to better manage processing.