I just pushed my first e-mail in Marketo. I set it to run once and received a may take several minutes to send message. It's been 20+ minutes. The send e-mail campaign light bulb is still greyed out, and I haven't received the email (I'm on the list of recipients). I'm wondering how long I should wait before being concerned that it didn't send for some reason? Is there a way to check if its sent?