Should OTOBO send out invititation with content-type application/ics ?

[bschmalhofer]

There is some ongoing work the improves the Calendar support in OTOBO. One part is that OTOBO sends invitations to calendar events. These invitations are iCalendar, https://www.rfc-editor.org/rfc/rfc5545, files that are sent out via Email, https://www.rfc-editor.org/rfc/rfc6047.
Currently the iCalendar file is sent out twice in a single message. First with content type text/calendar and then also as application/ics. This is in line with the best practices presented in https://devguide.calconnect.org/iMIP/iMIPBest-Practices. application/ics is apparently used by Google Calendar. But application/ics is not registered with the IANA, https://www.iana.org/assignments/media-types/media-types.xhtml.

I checked the invitations sent out by SOGo. These contain the iCalendar file only as text/calendar. Thus I propose to ditch application/ics in the invitations sent out by OTOBO.

The parser for incoming invitations and replies currently accepts:

• 'text/calendar'
• 'application/hbs-vcs'
• 'application/vnd.swiftview-ics'
• 'text/x-vcalendar'

[bschmalhofer]

On the other hand, Thunderbird sends out both content types.

See also https://stackoverflow.com/questions/42023140/inviting-event-attendees-programatically-on-ios-10/42065816#42065816 for a concist explanation of all those standards.

[bschmalhofer]

See also the question on Stackoverflow: https://stackoverflow.com/questions/75782030/should-icalendar-invitations-be-mailed-as-an-attachment-in-addtion-to-the-invita