Who I have the same questioned this topic

I followed the instructions to remotely retrieve voicemail (dial mobile#, enter # during the greeting message) but my problem appears to be that since my mailbox is full, I don't get my greeting. After dialing my cell# I get an announcement "the mailbox is full and cannot accept any messages at this time. Goodbye" and the call ends.  I tried entering a # during that announcement but it doesn't let me into my mailbox.  Do you have a suggestion? I want to empty my mailbox remotely.