If a scenario existed whereby there was a non exchange hybrid like lotus notes or group wise messaging platform and some users were using Office365 and co-existence was achieved by uploading all of the onpremise users’ as external contacts. Office365 users recipients have messages forwarded to from the source messaging platform. 

As you begin to convert the onpremise users’ to federated or managed users. You need to capture that user’s legacyexchangedn and ingest it into the users’ AD users’ proxyaddresses attribute as an x500 alias to prevent potential NDRs from existing Office365 users.

So run this Exchange Online command

get-mailcontact – resultsize unlimited | select-object legacyexchangedn,primarysmtpaddress | export-csv “csv file path” delete the first line 1 from the output of the csv

Then download this SCRIPT and edit the following lines

• edit line 11 and enter your domain name
• edit line 25 and enter your domain name

I normally use AD Modify to modify users’ UPNs. But it is only really practical when you are changing the UPN’s per OU. 

Lets say you were migrating from a different messaging platform , like Lotus Notes or GroupWise. But AD had the mailnickname attribute populated and the correct UPN added into your AD. To run the script you need to do the following

• Create a csv mail.csv and place it in the root C:\mail.csv. The heading of the csv will be ‘mail’ and then all the mailnicknames like sean@contoso.com
• On line 29 add in the distinguished name of the domain/forest scope
• Create a folder C:\logs to analyse any errors
• Watch out for ‘ which are acceptable characters in a smtp email address but unacceptable as a UPN in Office365.
• The script can be downloaded HERE.

After performing a migration from Lotus Notes to Exchange Online , Some users may see the following security pop ups when trying to click on doc links.

When using templates in Dell MFNE 4.1 , The template does not read the global settings defined in the tool.