This is the DNS setup:

name class type data time to live
sttstraining.com IN TXT v=spf1 include:_spf.google.com ~all 14400s (04:00:00)
sttstraining.com IN TXT v=spf1 mx include:infusionmail.com -all 14400s (04:00:00)
sttstraining.com IN TXT v=spf1 ip4:123.100.242.223 mx include:md02.com ~all 14400s (04:00:00)


Refer to the guide provided by google, it is not setup correctly, it should be a single record instead of multiple.
https://support.google.com/a/answer/4568483?hl=en&ref_topic=2759192

Pls combine them into 1 like below

sttstraining.com. 14400 IN TXT v=spf1 ip4:83.206.106.17 include:_spf.google.com mx include:infusionmail.com ip4:123.100.242.223 mx include:md02.com ~all