How to Automatically Delete Voicemails
Evolution supports emailing voicemails as attachments; in order for that to function an email address must be associated with a voicemail box.
Because Evolution can email the attachment some users find the need to manually clear out their inbox to be redundant. As a result you can configure the voicemail boxes to automatically delete voicemails.
In order to configure voicemail auto deletion, you will need to browse to 'Resources' → 'Voicemail' and, using the pencil icon to edit, or the 'New Record' link to create a new voicemail box, adjust the setting labelled 'Auto Delete':
In this example we have modified voice mailbox 710 to auto delete the voicemail messages after emailing them to firstname.lastname@example.org:
To enable auto deletion for the displayed voicemail select 'Yes; from the drop down, to disable it select 'No'.
Be sure to click 'Save' after making the change!