- Plesk Onyx for Linux
- firstname.lastname@example.org was specified as e-mail address specified for Let's Encrypt certificate in Domains > example.com > Let's Encrypt on the source server.
- After example.com was migrated to another server, email for Let's Encrypt certificate was changed to the default one (email of the site's owner).
This is Plesk bug #EXTLETSENC-570 which will be fixed in one of the next product updates.
There is no workaround currently except manually changing e-mail address in Domains > example.com > Let's Encrypt to correct one.