Why can’t I use Dropbox on a corporate network?
The Dropbox desktop app may not install or sync on corporate networks. If you’re not sure if Dropbox is supported on your corporate network, contact your organization's network administrator.
Some corporate networks are behind HTTP proxy servers that use NTLM authentication, which Dropbox currently doesn't support. However, some users have been able to use an intermediate proxy, such as NTLMAPS or cntlm, to run Dropbox on their network.