I'm trying to delete all 500+ voicemails in Google Voice. The query
in:voicemail is:unread seems return a promising list, but it only shows the first 10.
How can I delete them all at once?
Unfortunately, unlike Gmail, when you use the "Select All" checkbox and you have multiple pages of results, you don't get the "10 messages selected, click here to select all 501" (paraphrased) link.
I'm afraid your only option is to delete them 1 page at a time.
There looks like there should be some keyboard shortcuts that would help make this process less painful (
a to select all messages,
# to send to Trash) but they didn't work for me.
Google Voice is not a fully-baked product. I'm afraid it just doesn't have the features we have come to expect from Google.