We have an Exchange 2013 / Hybrid O365 deployment, with most of our mailboxes now on Exchange Online.
For a long time, our company has been using Distribution Lists that people outside the organization email to. This has led to a lot of emails being generated internally, to the mailboxes of the users on the DL.
We want to convert the DLs to Shared Mailboxes to reduce the amount of internal email generated.
Obviously we will need to create a mailbox and give the users permissions to it.
What is the best practice steps for converting a DL to a shared mailbox with minimal downtime?