Title: cPanel Webmail Error: UID SORT Internal Server Issue  
PrimaryCategory: Hosting  
Type: Procedural  
Tags: cpanel, webmail, mailbox_permission, dovecot_error, mailperm, troubleshooting  
Source UI Terms: None  
Source Reference: cPanel Webmail Error: UID SORT Internal Server Issue  

---

### Prerequisites:
- Root access to the server hosting the cPanel account.
- Knowledge of the cPanel account username affected by the issue.

### Steps:
1) Check the mail log file for permission errors:  
   ```  
   /var/log/maillog  
   ```
2) Look for entries indicating permission denied errors similar to:  
   ```  
   dovecot: imap(user@domain.com): Error: Mailbox INBOX: open(/home/user/mail/domain.com/user/cur/file,S=size:flags) failed: Permission denied (euid=uid(user) egid=gid(user) missing +r perm: /path/to/mailfile)  
   ```
3) Run the following command as root, replacing `username` with the actual cPanel account username:  
   ```  
   /scripts/mailperm username  
   ```
   This command resets the correct permissions for all mail-related files.

### Warnings:
- Ensure you have root privileges before running the command.
- Replacing `username` accurately is critical to avoid applying changes to the wrong account.

### Summary:
If you encounter a &quot;Server Error: UID SORT: Internal error occurred&quot; in cPanel Webmail, it is typically due to incorrect mailbox file permissions. Checking the mail log and running the `/scripts/mailperm` command as root with the affected username resolves this issue.

### Evaluation Pairs:
Q: What causes the &quot;UID SORT: Internal error occurred&quot; in cPanel Webmail?  
A: It is generally caused by incorrect permissions on the mailbox files.

Q: How can I check if mailbox permissions are causing the cPanel Webmail error?  
A: By reviewing the `/var/log/maillog` for permission denied errors related to the mailbox files.

Q: What command resets mailbox permissions to fix this Webmail error?  
A: Running `/scripts/mailperm username` as root resets the mailbox permissions.

Occasionally, while accessing the Webmail interface on a cPanel server, you may encounter the following error, and the inbox may fail to load: 
<pre class="language-markup" style="background: #efefef;padding: 8px;display: block;border: 1px solid rgb(204, 204, 204);overflow-x: auto;"><code>Server Error: UID SORT: Internal error occurred</code></pre>
This issue is generally caused by incorrect permissions on the mailbox files. Troubleshooting Steps
<ol><li style="font-size: 16px;">Check the mail log file: <pre class="language-markup" style="background: #efefef;padding: 8px;display: block;border: 1px solid rgb(204, 204, 204);overflow-x: auto;"><code>/var/log/maillog</code></pre>
</li><li style="font-size: 16px;">You may find entries similar to the following: <pre class="language-markup" style="background: #efefef;padding: 8px;display: block;border: 1px solid rgb(204, 204, 204);overflow-x: auto;"><code>Jan 20 09:05:25 bh-24.webhostbox.net dovecot: imap(sales@domain.com)&lt;1015847&gt;&lt;YL2Fl46cmel/AAAB&gt;: Error: Mailbox INBOX: open(/home/user/mail/domain.com/sales/cur/1423456500.H387374P1027032.bh-24.webhostbox.net,S=255260:2,) failed: Permission denied (euid=2945(user) egid=2945(user) missing +r perm: /home/user/mail/domain.com/sales/cur/1423456500.H387374P1027032.bh-24.webhostbox.net,S=255260:2,)</code></pre>
</li></ol>
Resolution This is a mailbox permission issue and can be fixed by running the following command as root:
<pre class="language-markup" style="background: #efefef;padding: 8px;display: block;border: 1px solid rgb(204, 204, 204);overflow-x: auto;"><code>/scripts/mailperm username
</code></pre>
Replace username with the actual cPanel account username. This script resets the correct permissions for all mail-related files and should resolve the Webmail access issue.

This article explains the cause of the “Server Error: UID SORT: Internal error occurred” message seen while accessing Webmail on cPanel servers. The issue is typically due to incorrect mailbox file permissions and can be resolved by checking the mail logs and resetting mail permissions using the appropriate system script.