The "Cannot write to cache directory /tmp/horde" message comes from the Horde webmail client. Horde is being retired from cPanel in favor of Roundcube, so the simplest fix is to switch to Roundcube, which is faster, actively maintained, and does not hit this error.
Use Roundcube Instead
Log in to webmail at https://yourdomain.com/webmail and choose Roundcube. It is the recommended webmail client on all our plans and is not affected by the Horde cache error. Your email, folders, and messages are the same regardless of which webmail client you open.
01. Why This Happens
Horde stores temporary cache files under your account's ~/tmp/horde directory. If the permissions on that folder are wrong - usually after a migration, a permissions reset, or a disk-quota event - Horde cannot write its cache and shows this error. Because Horde is on its way out, we recommend moving to Roundcube rather than repairing it.
Switching webmail clients does not move or delete any mail. Roundcube and Horde both read the same mailbox on the server - only the interface differs.
02. If You Still Need Horde Temporarily
While Horde is still available during the transition, you can clear the error by resetting the permissions on its cache directory:
- Log in to cPanel and open File Manager (enable "Show Hidden Files" in Settings).
- Find the
tmpfolder in your home directory, then thehordefolder inside it. - Set the
tmpandhordefolder permissions to0755(or0700), then reload Horde. - If your account is over its disk or inode quota, free up space first - a full account also blocks Horde from writing its cache.
This is a stopgap. Horde is being removed from cPanel, so move to Roundcube when you can to avoid the issue returning.
03. Related
See the Email Troubleshooting Guide for general webmail and mail-client help, or set up email on your device with our Outlook, iPhone/iPad, and Android guides.
Frequently Asked Questions
Why do I get Cannot write to cache directory /tmp/horde?
The message comes from the Horde webmail client when it cannot write to its cache. Horde is being retired from cPanel, so rather than patching it the recommended fix is to switch to Roundcube, which is faster, actively maintained, and does not hit this error.
How do I switch from Horde to Roundcube?
In Webmail, choose Roundcube instead of Horde when you log in, and set it as your default webmail client. Your email is stored on the server over IMAP, so all of your messages and folders appear in Roundcube exactly as they were.
Will I lose my email if I stop using Horde?
No. Your messages live on the mail server, not inside Horde, so switching to Roundcube or any IMAP client shows the same mail. Horde is only one way to view your mailbox, and moving away from it does not delete anything.
Is Horde being removed from cPanel?
Yes. cPanel is retiring Horde in favor of Roundcube, which is why new issues with Horde are not worth troubleshooting. Move to Roundcube now so you are not affected when Horde is removed.
Still Stuck on Webmail?
If Roundcube will not load or you are missing mail after switching, open a ticket and we will check the mailbox and account permissions for you.
Open a Support Ticket
