Maintaining originating sender IP address

When we look at the header of email processed by INKY we see change sender IP that causes delivery issues and DMARC failures specifically for those customers that use an external mail service. (for example Salesforce).

An example for a customer using sparkpostmail.com for relaying:

Without INKY:

Authentication-Results: spf=pass (sender IP is 192.174.94.29) smtp.mailfrom=bounce.mail.powerall.nl; dkim=pass (signature was verified)
Received-SPF: Pass (protection.outlook.com: domain of bounce.mail.powerall.nl designates 192.174.94.29 as permitted sender)
receiver=protection.outlook.com; client-ip=192.174.94.29;
Received: from mta-94-29.sparkpostmail.com (192.174.94.29)

What we see happening is if an email received from that mailservice is routed through INKY the IP address changed so the SPF check fails:

Authentication-Results: spf=softfail (sender IP is 18.198.39.243) smtp.mailfrom=bounce.mail.powerall.nl; dkim=fail (signature did not verify)

Received-SPF: SoftFail (protection.outlook.com: domain of transitioning bounce.mail.powerall.nl discourages use of 18.198.39.243 as permitted sender)
Received: from ipw.inkyphishfence.com (18.198.39.243)

Besides that, DKIM is also changed so that check also fails.

This caused emails to be Quarantined by Microsoft.

Is there a way to prevent this behaviour: Now we have to explain to customers that mail that is configured properly still gets quarantined. One customer missed a deadline because of this.