Bug? hotmail.com SPF errors

[kiamori]

This is an odd one for sure,

We have a client that is unable to receive emails from a hotmail.com customer, the error the customer is getting is:

Your message couldn't be delivered because the recipient's email system wasn't able to confirm that your message came from a trusted location.

For Email Administrators
This error is related to the Sender Policy Framework (SPF). The destination email system's evaluation of the SPF record for the message resulted in an error. Please work with your domain registrar to ensure your SPF records are correctly configured.

{mail server} gave this error:
The message was rejected because of Sender Policy Framework violation -> 554 This server requires you to send from an IP address specified by the SPF for hotmail.com


What is going on here?

Checking the logs shows that it was sent from 40.92.44.21

SPF record for hotmail.com is:

Code: Select all

v=spf1 ip4:157.55.9.128/25 include:spf-a.outlook.com include:spf-b.outlook.com include:spf-a.hotmail.com include:_spf-ssg-b.microsoft.com include:_spf-ssg-c.microsoft.com -all

[Admin]

If the MAIL FROM address in the SMTP logs is from hotmail.com then that SPF will pass. You can enable extra logging for the SMTP service:

https://www.mailenable.com/kb/content/article.asp?ID=ME020585

So it will show what it is doing with the SPF check. Possibly if this is an older version of MailEnable maybe there was a fix, but I don't recall anything along those lines.

[kiamori]

This was 10.45, and everything was correct, but it still kicked it back as spf fail.

Here are the logs with redactions:

08/17/23 17:24:49 SMTP-IN CBF29196CC8A48E99110C5D77A21ED07.MAI 61384 40.92.44.21 220 mail.server.tld service ready at 08/17/23 17:24:49 70 0
08/17/23 17:24:49 SMTP-IN CBF29196CC8A48E99110C5D77A21ED07.MAI 61384 40.92.44.21 EHLO EHLO NAM02-SN1-obe.outbound.protection.outlook.com 250-mail.server.tld [40.92.44.21], this server offers 7 extensions 267 52
08/17/23 17:24:49 SMTP-IN CBF29196CC8A48E99110C5D77A21ED07.MAI 61384 40.92.44.21 STARTTLS STARTTLS 220 Ready to start TLS 24 10
08/17/23 17:24:49 SMTP-IN CBF29196CC8A48E99110C5D77A21ED07.MAI 61384 40.92.44.21 EHLO EHLO NAM02-SN1-obe.outbound.protection.outlook.com 250-mail.server.tld [40.92.44.21], this server offers 7 extensions 197 52
08/17/23 17:24:49 SMTP-IN CBF29196CC8A48E99110C5D77A21ED07.MAI 61384 40.92.44.21 MAIL MAIL FROM:<{redacted}@hotmail.com> SIZE=15715 250 [SMTP:{redacted}@hotmail.com] OK. 42 50
08/17/23 17:24:49 SMTP-IN CBF29196CC8A48E99110C5D77A21ED07.MAI 61384 40.92.44.21 RCPT RCPT TO:<{redacted}@{redacted}> 554 This server requires you to send from an IP address specified by the SPF for hotmail.com. 95 44