More of the same here:
34.146.212.241 mail-amozvn.onthewifi.com
Very likely this is the same operator.
34.84.63.160 mail-amzne.3utilities.com
34.84.63.160 mail-amzn.servegame.com
34.84.63.160 mail-amzn.serveftp.com
34.84.63.160 mail-amzn.servehttp.com
34.84.63.160 mail-amzn.servebeer.com
34.84.63.160 mail-amzon.servebeer.com
34.84.63.160 mail-amzen.serveirc.com
34.84.63.160 mail-amzon.serveirc.com
34.84.63.160 mail-amzn.serveirc.com
34.84.63.160 mail-amzne.servemp3.com
34.84.63.160 mail-amzon.onthewifi.com
34.84.63.160 mail-amzn.myvnc.com
34.84.63.160 mail-amzen.servehalflife.com
It is unusual not to find Rakuten here too. They often mix the too.