Bounced Meeting Request with “550 5.1.1 RESOLVER.ADR.ExRecipNotFound; not found”

Is invisible delegate driving you nuts? Users will get a bounced message from Exchange Server for a mysterious delegate, like one below.

Subject: Undeliverable: <Subject Text>
Delivery has failed to these recipients or groups:
Jane Doe
The e-mail address you entered couldn’t be found. Check the address and try resending the message. If the problem continues, please contact your helpdesk.
Diagnostic information for administrators:
Generating server:
#550 5.1.1 RESOLVER.ADR.ExRecipNotFound; not found ##

Problem is a delegate’s mailbox was deleted and/or user account is disabled. Exchange mailbox is still having “hidden SID” about the disabled/deleted delegate information (in the current Boss’s mailbox).

Solution is easy. You will have to use Exchange Management Shell (powershell) to overwrite new existing delegates list.

I have seen on other forums that people are asking how do you remove an disabled delegate.  You can’t remove the invisible delegate. You can only overwrite the delegate list.

  1. Open Exchange Management Shell.
  2. Type Set-Mailbox -Identity "Mailbox Name" –GrantSendOnBehalfTo <Delegate User Names separated by coma>

On the command above, you have list all active delegates user names separated by coma.

E.g., Set-Mailbox –Identity BossMan –GrantSendOnBehalfTo “ExecutiveAdmin1”,”ExecutiveAdmin2”

One thought on “Bounced Meeting Request with “550 5.1.1 RESOLVER.ADR.ExRecipNotFound; not found”

  1. Hi
    thanks for your posting
    however in my case i am not able to track boss email id..
    thing here is that our change team sending meeting invite to 100’s of people and they are getting NDR for two people those are left to company.

    Strange is that NDR comes only when they send meeting and not for meeting minutes. i believe your article explains this why however i am not sure how to find out Boss email address since meeting is going to many people at a time.

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s