Yesterday I called MTS Data Card support but their IVRS system was failing in giving me my balance details. Eventually I decided to email their support and glad to say support email was also easily available on their website.
Today I saw acknowledgement mail in spam. No big deal but I usually dig around genuine mails which go in spam to find exact cause. In this case I found mail was sent to me from customercare.del@mtsindia.in and the server which relayed this mail was:
121.242.69.80 with rDNS pointer - mtsndmx1.mtsindia.in.
From email headers only one can tell main failure in mail:Authentication-Results: mx.google.com; spf=softfail (google.com: domain of transitioning customercare.del@mtsindia.in does not designate 121.242.69.80 as permitted sender) smtp.mail=customercare.del@mtsindia.in Thus clearly SPF failure. How?
“v=spf1 a mx include:elabs5.com ~all” “v=spf1 ip4:208.43.252.104 ip4:208.43.252.105 ip4:208.43.252.106 ip4:208.43.252.107 ip4:173.192.233.178/28 ip4:173.193.227.227/27 ~all”