I use both mailgun and a namecheap mail server (where I also have my domain) and when I receive mails in my gmail account, mailgun is recognized as a permitted sender, but that's not the case of namecheap. That's what I get:
Received-SPF: softfail (google.com: domain of transitioning xx@mydomain does not designate ... as permitted sender)
I have the following TXT record in my DNS
v=spf1 mx include:mailgun.org ~all
It's an IPv4 and I read some other posts in serverfault with no luck, so any thoughts on this will be appreciated.
EDIT
As stated here, Namecheap private mail sets up the MX records automatically and they are not shown on the DNS record list, I guess that has something to do with the fact that it was not recognized as a permitted sender when I had the MX record in the spf.