With the old system, even if voicemails didn’t get delivered you could still listen to them from the phone since the voicemails were stored as files on the hard drive and then also emailed.
With the IMAP stuff, I gather that the voicemails are only stored on the server and if that server is down you’ll lose the voicemail? What does the caller hear when the IMAP server is unavailable? Do they at least know that the voicemail wasn’t saved? Does the error occur before or after they try to leave a message (I’m assuming after)?
Thanks for all the information!