Hi Greg,
A few questions to help answer your question
What type of messages were missed while you were away (voicemail and/or SMS/chat messages)?
Also, which mode of communication were these messages missed on? For instance, was this your desk phone or from the Work Desktop or Mobile apps?
If we’re speaking of voicemail messages from a phone, there’s a few options to change the greeting from the voicemail menu.
Here’s a link to reference: https://support.8x8.com/equipment-devices/phones/general-phone-settings/how-to-set-announce-only-mode-for-voicemail-from-phone