About and error Number of MIME parts exceeds maximum permitted

Hello.

When we try to send an email to an account on the VPS that has Plesk, we get this error sometimes


Error Type: SMTP
Remote server (208.109.80.210) issued an error.
hMailServer sent: .
Remote server replied: 552 5.7.0 Number of MIME parts exceeds maximum permitted

Which could be the reason that causes this? is there any configuration on Plesk to set those MIME parts?

Thanks