It seems one of the installations is still on the 14 days Professional edition and second was already converted to Free edition automatically after the trial period expiration.
During 14 days Professional trial you can use SQLBackupAndFTP mail servers for sending email notifications, after the expiration of the trial period you can still use email notification option but you have to set your own SMTP Server.
To use email notification option with automatic mode using SQLBackupAndFTP mail servers, you have to purchase a license with Full-Service subscription.
Sorry, but according to your screenshot, you get an error message which says that you use “Automatic” mode for sending email notifications. Could you please check it?