Issue When logging into your webmail powered by Horde you get the message: "Unable to Retrieve Quota" and you can't view any emails. Solution This error is caused by Email headers not being generated properly from by a sender (Normally caused by spam) . To fix this problem:
- In the Horde inbox, click on "Options."
- Click on Display Options.
- You will see "General Options", "Message Options" and "Other Options." Under "Other Options" click on "Mailbox and Folder Display Options."
- Change "Default sorting criteria" to arrival time.
- That's it!