1. From your email Inbox (if you have Ooma Premier and your account is configured to send voicemail to email),
2. From your Ooma device (using the trash can button),
3. From the Telo handset (if you have a Telo and this optional device) and
4. Using the voicemail menu system from any telephone connected to any Ooma device.
If the method you are using isn't working, maybe you should consider trying one of the other 4 methods?
Formerly employed at another VoIP company.
My opinions are my own.