From this release (02/21) on it is possible to include an invitation when sending an email. The recipient can automatically add this to his / her calendar. You can add this option by going to Administration-Communication templates. Here you can select a template and add the option via the dropdown menu.

You can send an Ical invitation for the appointment date, quote appointment, expected end date, planned delivery date. You should definitely enter this date in the job so that it can be sent via the Ical invitation. ! Important: this option is only usable if emails are sent directly from PlanManager. This will not work if the config MAIL_TROUGH_OUTLOOK is enabled. Furthermore, these Ical attachments were automatically added to the template appointment specifications and repair appointments that are used by users of the Self Service Portal. No manual adjustment has to be made for the automatic mails from the Self Service Portal.