All of your email account that hosted with MultipleCloud cannot sent outgoing email by default. We take this measure to completely stop spam email in the first place.
For client’s domains that need to send outgoing email, please send us your domain list and we will place your domain to allow list. Otherwise, client’s domains cannot send email by default until we allow them.
This measure can completely stop spamming from abusive client and maintain the best IP reputation, We are sorry for any inconvenience and thank you for your understanding.