$ host duckduckgo.com
duckduckgo.com has address 46.51.216.186
duckduckgo.com mail is handled by 50 mx3.dnsmadeeasy.com.
duckduckgo.com mail is handled by 10 mail.duckduckgo.com.
duckduckgo.com mail is handled by 40 mx1.dnsmadeeasy.com.
duckduckgo.com mail is handled by 60 mx2.dnsmadeeasy.com.

$ host geti2p.net
geti2p.net has address 85.31.186.67
geti2p.net mail is handled by 100 mail1.welterde.de.
geti2p.net mail is handled by 200 mail2.welterde.de.