Any recommendations for 800 # Voice Mail?

Some years ago I was involved in an mlm program and used an inexpensive tollfree voice mail service to gather leads from people who would see our ads and call to leave their name and number. It was a flat monthly fee, maybe $20 a month but I don't recall exactly.

I need this type of service again but don't remember who they were. If any of you have used such a service please help. I need a two minute outgoing message with a capacity for around 30 messages at a time.

TIA