Using your own spoofed mail address.
See: https://toolbar.netcraft.com/site_report?url=pirro053.eldinn.com hosted by UPC Ceska Republica
GoDaddy domain by proxy. Nameserver IP: 77.48.123.51
Target : -ns2.eldinn.com
Org : "Ing. Petr Sramek - SPCom
City : Hradec Kralove
Region : 82
Also: https://toolbar.netcraft.com/site_report?url=viralbuza.com index page for “new domain”.
See: https://www.virustotal.com/#/ip-address/81.161.84.213
Also consider PHISHING: https://phishcheck.me/68620/details
More and more of this thing seen lately: https://laughingsquid.zendesk.com/hc/en-us/articles/360000955874-How-can-you-stop-spam-from-spoofing-an-email-address-
polonus