The shortcomings of the prior art are overcome and additional advantages are provided by securing display of sensitive messages to prevent third parties from viewing sensitive content. For one or more incoming messages designated as sensitive, substitute content to be displayed in place of sensitive content is received from a message recipient. Alternatively or additionally, an indicia to be displayed with any incoming message designated as sensitive is received from the message recipient. A message having sensitive content is designated as sensitive by a sender, a recipient, or an intermediate system. Upon receipt of a message designated as sensitive, a message window is displayed that includes substitute content different from the sensitive content. The substitute content includes an indicia that the sensitive content is not displayed.