Vacation Leave Request Workflow

Hi, I am very new to Nextcloud.

Is there an app or an external open source system that can be integrated to Nextcloud? Meaning we can access the whole system inside Nextcloud UI.

Automatic out of office reply messages are usually in the responsibility of the email server (MTA) or the email client (MUA) you’re using, therefore out-of-scope for Nextcloud.

Nevertheless several open source web based MUA exists, like e.g. Roundcube or Rainloop, etc. which should allow you to configure such messages. For the second a Nextcloud app exists to integrate the GUI into the Nextcloud environment.