Using an option button on the message toolbar you can choose to create a self-extracting file rather than a zip. This feature is for recipients who don't have an unzip utility that enables them to view or open items in a zip file. ZipOut won't create the self-extracting attachment if the self-extractor would be as large or larger than the original uncompressed attachments. Instead the original attachments are left on the message and the message is sent without a self-extracting file. You also have the option of making self-extractors the default, but that feature is principally for the Outlook user who consistently sends message attachments to recipients without ZipOut or a Zip utility.
When a recipient of a message with a self-extracting file attachment opens the message, they will see a ZipOut Self-Extractor icon that represents the compressed attachment(s). If the recipient double-clicks the attachment icon, the ZipOut Self-Extractor Shell will open to display the contents of the attachment.
Warning Self-extracting files are executable (.exe) files. Many e-mail programs (including Outlook with the Outlook E-mail Security Update installed) block .exe attachments because they are vectors for e-mail worms and viruses. Send .exe attachments with extreme caution and realize that the recipient of your message might not be able to open the attachment.