Publishing an iCalendar file allows a mail user to take a local calendar and push the entire contents of the calendar to the MailEnable server, as a hosted file which is accessible by various clients. Whenever the user makes a change to the calendar, the client application uploads the entire calendar to the server. Thunderbird (with the Lightning extension) and Microsoft Outlook can be configured to automatically re-publish the calendar to the server whenever you make changes to a local calendar. They can also periodically update themselves with a copy of the calendar from the server.

When a client makes a change to the published calendar, the mail client will fetch the entire calendar from the server, applies the change and then upload the modified calendar to the server.

A mailbox owner can publish multiple calendars and these calendars are able to be accessed as hosted iCalendar (.ics) files by e-mail clients. The owner of the mailbox is able to see the list of published calendars by logging into webmail and viewing the Shares under Options. Published calendars will appear under the Calendar folder in the list of shares. The mailbox user can delete these items if needed, or they can be removed by the client application which uploaded it.

Published calendars are by definition available for read by the public. You can control the level of access for public users under the Options | Shares menu of the MailEnable WebMail client. The level configured affects all uploaded iCalendar files. Anyone providing the correct username/password for the mailbox will be given full access.

The following table lists URLs for connecting to mailbox calendars. Be aware there is a lot of difference in how clients use URLs, so this should only be used as a overview, and you should see specific documentation for each email client for correct usage.