Gmail couldn't verify that domain.com actually sent this message (and not a spammer)

Gmail couldn't verify that domain.com actually sent this message (and not a spammer)

I have my DKIM set up, and followed the guide on how to set up SPF in TXT records, but I still can't verify my SPF in my control panel and when I send email, I get the "gmail couldn't verify..." message. My domain is dl-industrial-supply.com. Any help would be apprecaited!