郵件開不了附件

電郵出現以下的文字, 開不了附件怎解決?

Spam detection software, running on the system "box545.bluehost.com", has
identified this incoming email as possible spam. The original message
has been attached to this so you can view it (if it isn't spam) or label
similar future email. If you have any questions, see
the administrator of that system for details.