Are there security level settings for Mail.app?
I am using Mail.app on a Mac running Mac OS 10.13. I am trying to set up a new account with an online company, using my Gmail email address. Verifying my address is a required step in the process. They claim they are sending a confirmation email to me, but I am not receiving the email. It is apparently being blocked by the Gmail servers due to something about SPF (Sender Policy Framework). I reported the issue and the tech support folks at the company wrote back and said This is related to firewall setting of your email and you should check junk mailbox. Your email security is set too high, with SPF service enabled, so it automatically blocks our cloud mail. But I don’t see any email security level settings in either Gmail or Mail.app so I'm not sure what he is talking about.
BTW, I deleted the account and re-registered it using my iCloud email address instead, and their confirmation email came to my inbox within seconds of clicking Verify Email, so this appears to be an issue with Gmail blocking their emails, not a Mac issue.
Has anyone else had this issue? Are there any workarounds? I don’t like to create accounts using my iCloud address because it invites spam, which is why I have the Gmail address for such purposes.
Thanks for any help with this.
MacBook Air, macOS High Sierra (10.13.3)