- Plesk for Linux
Mail for the domain example.com is hosted on an external mail server:
# host -t mx example.com
example.com mail is handled by 0 mail.example.org.
# host -t a mail.example.org
mail.example.org has address 203.0.113.2
Mail to that domain cannot be sent from a different domain hosted on Plesk server:
CONFIG_TEXT: The mail system firstname.lastname@example.org: mail for example.com loops back to myself
DNS zone is hosted externally:
# host -t ns example.com
example.com name server ns1.he.net.
example.com name server ns2.he.net.
DNS zone is enabled on the local Plesk server in Domains > example.com > DNS Settings, and has no MX records, or has the MX records that point to the local server
Postfix queries local DNS server and sends mail locally using it.
Navigate to Domains > example.com > DNS Settings
Change or add the MX record corresponding to the data on the external DNS server
Change or add the corresponding A record for the MX record corresponding to the data on the external DNS server