Identify the exact email address and its authorized owner. Prepare a unique strong password and list devices or applications that need updating. If the mailbox may be compromised, also plan to review forwarding rules, filters and recent account activity.

1. Sign in to Plesk with permission to manage the domain mailboxes. Open Mail and select the exact address.
2. Locate the password fields in the mailbox settings. Enter and confirm a new strong password, or use the available generator and store the result securely.
3. Save the change and read the confirmation. If the mailbox is linked to an additional Plesk user, review any related account-access behaviour shown by the form.
4. Update authorized mail clients and SMTP applications promptly so they do not repeatedly retry the old password.
5. Test a new webmail login with the full email address, then test sending and receiving from a configured client.

Confirm the new credential works and the expected devices reconnect. Keep the password in the owner approved password manager rather than in a plain-text support conversation.

If a client still fails, check its incoming and outgoing authentication settings separately, since it may store two password entries. A stale saved password can cause repeated lockouts. For suspected compromise, review persistent forwarding, application access and active sessions through the supported server workflow. Rotating the password alone does not remove messages already copied by an attacker or fix a compromised device.

• Creating an email mailbox in Plesk
• Opening Plesk webmail securely
• Renaming an email address in Plesk

• Plesk: Changing Mail Account Password