Hi Rochelyn,
From Manage / System / Security, you might try to setup the "Allowlist email domains" value.
Use this parameter to set an allowlist of email domains. When the parameter is set, emails can be sent only to the specified email domains. The value is a comma-separated list of domains, for example: ibm.com, domain.com, mail.com. If no value is specified, any email domain can be sent a message.
If it is not working, you probably need to contact IBM Support.
Best regards,
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Patrick Neveu
Positive Thinking Company
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