Some attachments not downloading with Gmail
Also, a format of attached files that is sent by Outlook (TNEF) is not supported if your mail server does not convert them. These will be ignored by the program. If the attachment still doesn't download, contact issues@gearmage.com.
If this still does not help, follow the troubleshooting steps here: https://gearmage.uservoice.com/knowledgebase/articles/469888-troubleshooting-attachment-problems-or-issues-s