no seu caso
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hq IN MX 5 ALT1.ASPMX.L.GOOGLE.COM.
hq IN MX 5 ALT2.ASPMX.L.GOOGLE.COM.
hq IN MX 10 ASPMX2.GOOGLEMAIL.COM.
hq IN MX 10 ASPMX3.GOOGLEMAIL.COM.
qh IN MX 10 ASPMX4.GOOGLEMAIL.COM.
hq IN MX 10 ASPMX5.GOOGLEMAIL.COM.
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*.domain.com. IN MX 10 mxa.mailgun.org.
*.domain.com. IN MX 10 mxb.mailgun.org.