You have created an e-mail and already linked the attachment. Because you want to continue later, you save the e-mail to continue later. When reopen your e-mail you will see that the attachment that you´ve selected with the AttachingIT plug-in has disappeared. We are happy to explain why:
This has to do with how Outlook handles storing these files. From a technical point of view, it is currently not possible to ensure that Outlook also saves the linked attachments.
That is why you have to re-select the attachment before sending an e-mail.