Add entries to a user's Outlook Trusted and Blocked senders

To add "contoso.com" and "fabrikam.com" to jsmith@example.com's Outlook Trusted Senders list, and add "jane@adatum.com" to their Blocked Senders list, without affecting existing entries:

Set-MailboxJunkEmailConfiguration -Identity jsmith@example.com -TrustedSendersAndDomains @{Add="contoso.com","fabrikam.com"} -BlockedSendersAndDomains @{Add=jane@adatum.com}

To view the user's list of Trusted Senders:

(Get-MailboxJunkEmailConfiguration jsmith@example.com).TrustedSendersAndDomains

And to view Blocked Senders:

(Get-MailboxJunkEmailConfiguration jsmith@example.com).BlockedSendersAndDomains