Ok, i have got answer form Administrator Manual (I know, RTFM

, page 65:
"Mailserver: Please select if the local mail server or an external mail server is responsible for
treating emails addressed to the host + main domain of the site (e.g.
www.domain.tld) (see
chapter III−2.3.3)."
So, I can freely change the mail server to External under site (eg: hostname.domain.tld) because under Co-Domains i still have the main domains' (eg: domain.tld) mail server configured to be local.. i see. smart
Recent comments
1 day 3 hours ago
1 day 4 hours ago
1 day 9 hours ago
1 day 15 hours ago
1 day 16 hours ago
1 day 17 hours ago
1 day 22 hours ago
2 days 4 hours ago
2 days 8 hours ago
2 days 10 hours ago