I want to have this setup as optimal as possible, I think I understand and have this correct but would like an experts opinion. Info is fake, to protect the innocent. :)
Mail server is at clients site. This and the backup MX record are the only two sources that can deliver email for this domain. Office public IP which is static is 18.104.22.168/32. The reverse DNS and A record for the mail server is mail.domain.org. The backup MX record address is bu.backupmxserver.com.
Here is what I have:
"v=spf1 mx a ip4:22.214.171.124/32 a:mail.domain.org include:backupmxserver.com -all"
Should I include/exclude anything given this information? If I need to provide more info, please let me know.
Also, is the syntax the same for TXT and SPF? I could use what I have here for both?
I used this wizard to get what I have so far: