The service desk feature enables user to create issues by sending emails to OneDev. Issues can be discussed over email completely, without the need of logging to OneDev.

System email address defined in mail setting should be used as recipient of such email, and project name may be appended to this address using to indicate where to create issues. For instance, if system email address is specified as support@example.com, sending email to support+myproject@example.com will create issue in myproject. If project name is not appended, OneDev will look up the project using project designation information below

NOTE: Service desk only takes effect if mail setting is defined and its check incoming email option is enabled. Also sub addressing needs to be enabled for the system email address. Check this tutorial for details