I need to add a spf record to avoid spoofing and I use register.com as dns provider. They told me to add the following into the txt record.
@ "v=spf1 include:spf.registeredsite.com ~all"
I did that. When I sent a test mail to my gmail account, the mail went through but the header showed me it is has a softfail and the error message is as following:
pf=softfail (google.com: domain of transitioning firstname.lastname@example.org does not designate 192.168.0.1 as permitted sender) smtp.mailfrom= email@example.com;
For your information, my A record is the following:
*.mysite.com 10.10.0.1 <- webserver
mail.mysite.com 192.168.0.1 <- emailserver
Note: Please pardon the email address and ip addresses in this post are not real for security reason.