Provide Send-As Permission to Shared Mailbox through Security group

[frankzz]

Hello People,

I am trying to provide Send As permission to a Shared Mailbox and a O365 group through a Security group.

My exact case here is, I am performing a User Onboarding Automation through Power Automate and tried adding the permission through Mail Enabled Security group, which doesn't work from PA.

Hence I did the below

1. Ran the script Add-RecipientPermission sharedmailbox@domain.com -AccessRights SendAs -Trustee MailEnabledSG. To provide Send As Permission to Mail Enabled Security Group.

2. Add-DistributionGroupMember -Identity MailEnabledSG@domain.com -Member SecurityGroup.

Under the security group members are added, however it's been more than 24 hours and it do not shows any positive results. Can someone help me ?

[#2]

Hello, did you try to do that via Exchange Admin center user interface?

[#3]

Hey Victor

I cannot add Security group via EAC, We have option only to add Mail Enabled Security Group

[#4 · Accepted solution]

I did not test it myself but I believe it will work only for mail-enabled security groups.
Could you transform your security group to a mail-enabled one?

[#5]

I have added the user straight to the mail enabled security group and tried accessing the shared mailbox. But it throws an error as 'Access Denied'. Do you know how long it takes for the sync ?

Nowadays I am facing huge delay in sync of permissions 😞

[#6]

On my tenant it takes about 30 minutes.

[#7]

Finally it worked with Mail Enabled Security group, by any chance to do you know if it's possible that permissions for shared mailbox can be assigned through distribution list ?

[#8]

No I do not know. Just try to do that yourself.