Step 3: Import Mailboxes (Google Workspace)

All of your active mailboxes, including users, shared mailboxes and distribution groups, should be added to Proofpoint ahead of the setup. This is done by importing a list of your mailboxes from a CSV file.

Accepted format

Proofpoint will only accept a CSV file with the following columns. No header row is required.

1. First name
2. Last name
3. Primary email address
4. Mobile phone number
5. Aliases, optional, one per column

• Each field is separated by a comma and each mailbox sits on its own row.
• Everything after the mobile number column is treated as an alias.
• The mobile number column has to be present, but the value can be empty if two factor authentication for users is turned off.
• A valid mobile number must include an international prefix and no other non-numeric characters.

One user with one alias:

John,Smith,john.smith@domain.com,+447123456789,jsmith@domain.com

One user with no mobile number and two aliases. Note the empty field between the two commas:

Jane,Doe,jane.doe@domain.com,,jd@domain.com,jane@domain.com

Export the user list from Google

1. Sign in to the Google Admin console at admin.google.com using an administrator account.
2. Go to Menu, then Directory → Users.
3. At the top of the Users list, click Download users.
4. Under Select columns, choose All user info columns and currently selected columns.
5. Under Select format, choose Comma-separated values (.csv), then click Download.
6. The export is queued as a task. When it finishes, open the link in the task list to retrieve the file.
7. Delete every column except the four Proofpoint expects, and remove the header row.

Export groups and shared mailboxes

Directory → Users does not include groups. This is a separate export and it is the step most often skipped.

1. Go to Menu, then Directory → Groups.
2. Export the group list as a CSV.
3. Add each group address to the mailbox CSV as its own row. The first and last name fields can be the group name and a placeholder.

Shared mailboxes on Google Workspace are normally either a group or a full user account. If it is a user account it will already be in the user export. If it is a group it will not.

Import mailboxes into Proofpoint

1. In Proofpoint, navigate to User Management → Import & Sync → CSV Import.
2. Choose whether to import these mailboxes as End Users or Silent Users. End Users receive a welcome email and access to the Proofpoint portal, Silent Users do not.
3. Click Choose File to retrieve your CSV of mailboxes, then click Upload.
4. Read the import result. Proofpoint reports the rows it rejected, most often for a malformed mobile number or a duplicate address. A partial import that nobody checks is the same as a missing mailbox.

Convert non-users to functional accounts

Any imported mailboxes will appear in the Proofpoint user list by default. If any of these are shared mailboxes or distribution groups and should not count as active users, these can be converted to functional accounts through the following steps:

1. Navigate to User Management → Users on the left side of the screen.
2. Select the users you would like to change, then click Mass Update Users.

3. Change the Role drop-down to Functional Account, then click Update Users at the bottom of the window.

Before moving on, compare the user count in Proofpoint under User Management → Users against the number of rows you imported plus the groups you added. A mismatch here is the most common cause of bounces after cutover.

Proceed to next step: Step 4: Configure Google Workspace for Proofpoint