Sometimes calls go to voicemail before I can pick it up. Can I change the delay time?

In Skype for Business the standard time before a call is transferred to voicemail is 20 seconds. 

If you want to set another time frame (or alter a number of other settings), simply click the little telephone icon at the bottom of Skype for Business and click Setting for forwarding calls. 

Click Voicemail after 20 seconds and change it to your preference.

Click OK to enable the settings.