Add an emailaddress to the safe senders list in Outlook for all Office365 mailboxes

 Adding an email address to be trusted for whatever reason to your environment depends on what email anti spam/phish/malware/virus solution you have.

But here's one that's always in the way. Outlook.

Here's how to add an email address to the safe senders list in Outlook for all your mailboxes in Exchange Online:

#Add trusted sender and domain per user:            
Set-MailboxJunkEmailConfiguration firstname.lastname@domain.com  -TrustedSendersAndDomains @{Add="@something.com","info@something.com"}             
            
#Add Blocked sender and domain per user:            
Set-MailboxJunkEmailConfiguration firstname.lastname@domain.com  -BlockedSendersAndDomains @{Add="@something.com","info@something.com"}            
            
#Add emailaddress to the trusted list in all mailboxes:            
Get-Mailbox -resultsize unlimited | Set-MailboxJunkEmailConfiguration -TrustedSendersAndDomains @{Add="quarantine@messaging.microsoft.com"}            
            
#Add a domain and an email address to the trusted list in all mailboxes:            
Get-Mailbox -resultsize unlimited | Set-MailboxJunkEmailConfiguration -BlockedSendersAndDomains @{Add="domain1.com", "user@domain2.com"}