Cron/WP-Cli Alternative

I am using a shared hosting service that won’t let me use WP-cli, or I don’t want to use it. Is there an alternative to setting up a cron job to call the script? I want to be able to use the reply by email feature without having to use wp-cli, and I’m sure some other people might like this as well.

Thanks for the great plugin1

http://wordpress.org/extend/plugins/p2-by-email/