Unable to remove IP address when it is used for Send mail from specific IP feature: The IP address 203.0.113.2 is already used for hosting

Symptoms

• In an attempt to remove 203.0.113.2 IP address in Plesk > Tools & Settings > IP Addresses, the following error is shown and as result, it is not clear where the affected IP address is used:

  PLESK_ERROR: The IP address 203.0.113.2 is already used for hosting

• This address is not used by any domains or resellers.

• The 203.0.113.2 IP address is set in Tools & Settings > Mail Server Settings > Send mail from specific IP.

Cause

This is the Plesk bug with the ID #PPPM-5911, which will be fixed in the next Plesk update releases.

Resolution

1. Log in to Plesk.

2. Go to Tools & Settings > Mail Server Settings > Outgoing mail mode.

3. Select the Send from domain IP addresses option:
   Click on the screenshot below to expand

   
4. Scroll down and press the OK button to apply the changes.