Mail sending blocked by ProofPoint

Mail sending blocked by ProofPoint

Hi,

We are having problems sending mail from one of our zoho.eu mail accounts:

Reporting-MTA: dns; mx.zohomail.eu

Arrival-Date: Wed, 17 Jun 2020 11:20:24 +0200

Original-Recipient: rfc822; "XXXXXXXXX" <XXXX@aecom.com>

Final-Recipient: rfc822; XXXX@aecom.com

Status: 554

Action: failed

Last-Attempt-Date: 17 Jun 2020 09:30:00 GMT

Diagnostic-Code: XXXX@aecom.com, ERROR_CODE :554, ERROR_CODE :Blocked - see https://ipcheck.proofpoint.com/?ip=31.186.226.238

It seems that the IP 31.186.226.238 is blacklisted. Is it possible to unblacklist it?

Regards,