Forum Discussion

ExpertLMS's avatar
ExpertLMS
Copper Contributor
Aug 27, 2026

Safe senders list for a Shared Mailbox

Good morning

We have a shared mailbox for support. When we reply to a customer, we include this email address in CC. A member of the team accidently marked the shared box as spam - and can we get it back to a "safe sender"???? NO!

I cannot believe how difficult this task seems to have been so far. We've tried setting rules, looked in Defender and Exchange, even tried Powershell stuff. If our support email is included in TO or CC it drops into Junk. If we manually move the message or ask it to be unblocked we just get the following:

 

I don't understand why we cannot add ourselves as a safe sender. Can anyone PLEASE help practially to help us? Many thanks.

 

1 Reply

  • RobertSparnaaij's avatar
    RobertSparnaaij
    MVP
    Aug 28, 2026

    I think you got yourself stuck with Blocked vs Safe Sender thinking.

    Undoing a Blocked Sender isn't making it a Safe Sender but making it a neutral sender again.

    So, all you have to do is taking the sender of the Blocked list and your done.

    Someone who has Full Access permissions to the mailbox can do this in the following way;

    • In Outlook when the Shared Mailbox is configured as an additional account.
    • In Outlook on the Web when opening the mailbox via "Open another mailbox"

    An Exchange admin can do this via the Set-MailboxJunkEmailConfiguration cmdlet.

    Example;

    Set-MailboxJunkEmailConfiguration "Support" -BlockedSendersAndDomains @{Remove="spamSMTPaddress"}

    Addresses belonging to domains of your Exchange environment are considered Safe Senders by Outlook by default and therefore can't (and don't need to) be added.