Emails sent through Microsoft Outlook will not allow PDF attachments
We use Microsoft Outlook for work emails and for some reason are no longer being allowed to send any PDF attachments. Once you send them they are showing up in the "outbox", but a message stating "Oulook has already begun transmitting this message" shows up. I sent an email yesterday and checked this morning and it still has not been sent. It also does not show up in the "sent" folder. Any ideas what can be done? Or how it got this way?
Any help would be so appreciated.