I'm having the same issue. I know that the issue is specific to Cox email accounts because I am able to replicate the issue across 2 different email accounts. The security code is supposed to come from account-security-noreply@accountprotection.microsoft.com. However, the email is never received. Checked Spam and Junk folders - nothing there. Checked via WebMail and MS Outlook desktop application (to rule out issues specific to the desktop application) - same result, no password reset email in sight. But this only happens with Cox email accounts. I have my gmail account linked to a Microsoft account, and I clicked the option to reset the password on that Microsoft account, and it came through just fine through Gmail's mail servers. But with Cox, it doesn't come through. So I reached out to Microsoft, and they asked me to check with Cox to make sure that the following Microsoft SMTP server addresses are whitelisted by Cox:
Microsoft SMTP server IP addresses:
111.221.26.11
111.221.26.12
111.221.26.13
111.221.26.14
111.221.26.15
207.46.200.25
207.46.200.27
207.46.200.28
207.46.200.29
207.46.200.30
207.46.50.221
207.46.50.222
207.46.50.223
207.46.50.224
207.46.50.225
65.54.121.78
65.54.121.79
65.55.240.71
65.55.240.72
65.55.240.73
65.55.240.74
65.55.240.75
65.55.52.229
65.55.52.230
65.55.52.231
65.55.52.232
65.55.52.233
65.55.52.234
65.55.52.235
65.55.81.54
65.55.81.55
94.245.112.10
94.245.112.11
94.245.112.17
94.245.112.18
94.245.112.19
I called Cox and they said a network engineer would get back to me, but I have not received a call. If Cox adds the above SMTP servers to their whitelist, as well as senders with the domain accountprotection.microsoft.com, I think this will resolve the issue. I appreciate your help in this matter, and I'm sure everyone who has a Microsoft account linked to a Cox email address will too.
Note: To replicate the issue, all you have to do is go to https://login.live.com/, enter your Cox email account that you signed up to link to a Microsoft account, click Next, then click "Forgot password?". Then click "Next" to request that a reset code be sent to your email address. It'll say "We just sent a code to *@cox.net", but the email is never received.
