Setup separate Email server and DirectAdmin website using the same domain

[RedBlade]

Hello guys,

I've tried many advises/articles in D.A forum but couldn't find the right solution.

I use the domain pvtrans.com for:
- Email server (MX: mail.pvtrans.com)
- A website in DirectAdmin.

In DNS Administration settings, "Local Mail Server" for pvtrans.com is disable. Below is the DNS Control page for this domain:

ftp A 10.10.11.11
ftp A 115.146.127.60
localhost A 127.0.0.1
mail.pvtrans.com. A 203.128.242.59
pacific A 10.10.11.11
pacific A 115.146.127.60
pvtrans.com. A 10.10.11.11
pvtrans.com. A 115.146.127.60
www A 10.10.11.11
www A 115.146.127.60
www.pacific A 10.10.11.11
www.pacific A 115.146.127.60
pvtrans.com. NS dns17.fpt.vn.
pvtrans.com. NS dns18.fpt.vn.
pvtrans.com. NS ns1.vdc3.vn.
pvtrans.com. NS ns3.vdc3.vn.
pvtrans.com. MX 10 mail.pvtrans.com.
localhost AAAA ::1

Should I change/modify the MX record or DNS setting to something else?

Currently, when system emails (or build-in webmail) send to email belong to @pvtrans.com (eg: [email protected]), it will not be delivered with this error:
"2016-03-16 22:24:20 [email protected] R=lookuphost defer (-1): lowest numbered MX record points to local host
*** Frozen"

If I modify some settings, the email is frozen again with this error: "R=virtual_aliases"

This domain is already present in etc/virtual/domain and domainowner. Other configs for an external email server is already set.

Please support me if you've experienced this before.

Thank you and have a good day!