Change a mailbox password or storage quota

Control Center can change the password of an enabled mail-only account and display its storage allowance. Quota changes remain in Virtualmin or require support. Use the mailbox password for email; it is separate from your customer account and hosting-owner credentials.

1. In Control Center, open Hosting services → Manage website → Email for the domain. Locate the address and its Mailbox username.
2. Expand Change password for [address]. Enter matching New password and Confirm new password values of 12-128 characters without line breaks. Save the new password securely; it will not be available to reveal later.
3. Select I understand I must update this password in my email apps, then Save new mailbox password. Wait for the result. Allow at least one minute before another password-change attempt.
4. Update every phone, computer, website form, or other application using this mailbox. Check outgoing SMTP credentials as well as incoming credentials; applications may store them separately. Use the new password for the next Roundcube login.
5. Review Storage allowance when shown. For actual usage or a quota adjustment, choose Open Virtualmin, select this domain, and inspect Edit Users. A larger mailbox quota remains subject to the hosting account's overall capacity.
6. If more space cannot be assigned, export and verify messages you need, then remove unwanted mail. Review Sent, Trash, and Junk as well as Inbox. Emptying Trash permanently removes its contents.

Disabled mailboxes do not offer password changes here. Restore a dashboard-paused sign-in first, or ask support about other disabled states. Users with FTP, database, or other additional access must be managed in Virtualmin; its password guide describes Edit Users → Set to → Save.

Check the result: Sign out and back in with the new password, then send and receive a test message. For a storage change, refresh usage after cleanup and confirm there is free space. Usage displays may not update immediately.

Common problems: If the change cannot be confirmed, try signing in with the new password before retrying. Repeated prompts can come from an old saved password or the wrong username. Other mailboxes and website data also consume shared storage. Send support the error text, never the password.

Related: Pause or restore sign-in, Connect an email app, Export a mailbox.