- Plesk Onyx for Linux
An attempt to remove IP address in Tools & Settings > IP Addresses fail:
PLESK_ERROR: The IP address 203.0.113.2 is already used for hosting
This address is not used by any domains or resellers;
203.0.113.2IP address is selected in Tools & Settings > Mail Server Settings > Send mail from specific IP;
The misleading error message is considered as a Plesk bug #PPPM-5911, which will be fixed in the next major Plesk release.
Select the Send from domain IP addresses option in Tools & Settings > Mail Server Settings > Send mail from specific IP: