O365 / Exchange 2010 Hybrid - Recipient not found by SMTP address lookup

[CapnPugwash]

Hi,

With O365 & on-prem Exchange 2010 in a Hybrid config we successfully migrated all staff mailboxes to O365.

 

New staff obviously don't have a mailbox to migrate, a mailbox is created within O365.

 

We have several MFDs with a 'Scan-To-Email' function. This works by sending an email from the users email address to themselves.

The MFD's point to the on-prem Exchange 2010.

 

This doesn't appear to work for new staff. They get no emails. It looks like the request gets pushed through to Exchange 2010 but nothing happens.

 

Looking at the staff members attributes in AD I saw that that the new staff had no 'target address' attribute value.

I have added the correct setting (comparing it to accounts that do work)

 

When the new staff now try to use 'Scan-To-Email' , emails are pushed out of the local Exchange to O365... and the user receives an email notification ( a bounce-back, including the scan-to-me email) saying that the email couldn't be delivered because the user is unknown!

 

Reported error: 550 5.1.10 RESOLVER.ADR.RecipientNotFound; Recipient not found by SMTP address lookup

 

I'm sure this is something simple, can anyone advise?

[CapnPugwash]

In case anyone is looking; the new staff have neither a legacyExchangeDN attribute value nor do they have an x500 proxy address.

 

I believe this explains the above behaviour.. alltho' I'm not sure how to correct it!

[CapnPugwash]

Think I'm sorted, just need to mail-enable the accounts without setting up an on-prem mail box

 

Running this in Exchange should do the trick

Enable-MailUser -Identity John -ExternalEmailAddress [email protected]

 

As almost all of our users' mailboxes are now in the cloud, I guess I should really be thinking about killing the Exchange server / Hybrid config.