vmail outbox has many messages

sorry if this is a newbie question but i can't find it in the manual or searching this forum.

maybe i don't have a fundamental understanding of vmail. i understand it's not a mail server. but when i get a message from someone, i see an alert to remind me to pick it up. so why are there 9 messages in my outbox in the last 3+ weeks? is it something i'm doing wrong? are others not picking up their mail?

thanks very much, tom wa2uvc