Linux Harbour

We installed a number of Horde IMP webmail on our clients and our own email systems for years. One of our clients reported that sometimes he and his colleagues cannot send emails on webmail.

Recently we googled the problem again, and found a FAQ for Horde IMP matched his problem. It is a problem only occurs to IE users due to security setting of IE/Windows.

Internet Explorer cannot send messages

After composing a message with Internet Explorer and hitting send, the message is not sent and the user either sees a blank page or is returned to an empty message composition page. This has to do with IE's privacy settings.

If the privacy settings are set to "Medium High" or above and a privacy policy is not set on the server, then users may experience this problem. This issue can be resolved either by modifying the clients, or by adding a privacy policy to the server.

If the number of Internet Explorer clients is small, it may be feasible to change the clients. Ask users to do one of:

1. Use a different browser
2. Lower Internet Explorer's privacy setting to "Medium". (Please note that this may increase the risk that users will experience malware.)
3. In Internet Explorer's privacy options, set the IMP server to always allow cookies.
   And I found a case study on P3P and IE6 should be helpful to solve the problem.