Messages Stuck in Mail App Outbox

I have an iphone 4S with IOS 6.1.3. I use the Gmail app with no issues to send and receive messages. However, when I attempt to send mail attachments directly from the phone's voice memos or camera roll functions, the messages get stuck in the Mail app outbox. I receive no warning that there is an error when sending these messages, they just never send and I find them sitting in the outbox. I've tried resending from the outbox with no luck.

For camera roll pictures, I've gotten around the problem by composing a message in Gmail and then browse and attach the photos to the e-mail. I don't think there is a similar solution for voice memos. The only options within voice memos is to either directly e-mail or text the memos (but e-mail isn't working). I don't see a way to save the memo and attach them like pictures as I can do in Gmail.

I would love to be able to actually send emails directly from voice memo and/or camera roll, but I'm also open to work-arounds.