Outbound emails of some customers from the EMEA region are not being sent and the following error message appears:
“Your message wasn't delivered due to a permission or security issue. It may have been rejected by a moderator, the address may only accept e-mail from certain senders, or another restriction may be preventing delivery.”
To resolve the problem, enable Outbound Filtering and then specify an Outbound IP Address in HES 2.0: