How to Migrate Mail Contacts from Exchange to Office 365? Guide

When an organization moves from an on-premises Exchange Server to Office 365, migrating mail contacts is also important. Mail contacts store external recipients' names and email addresses, helping employees communicate with people outside the organization.

If these contacts are not transferred properly, users may lose access to important recipient details in the new environment. Here are some simple methods to migrate mail contacts from Exchange to Office 365.

Methods to Migrate Mail Contacts from Exchange to Office 365

Method 1: Export Mail Contacts from Exchange Using PowerShell

You can export existing mail contacts into a CSV file using Exchange Management Shell.

1. Open Exchange Management Shell.
2. Run the following command:

Get-MailContact -ResultSize Unlimited |

Select-Object Name,DisplayName,FirstName,LastName,ExternalEmailAddress |

Export-Csv "C:\Contacts.csv" -NoTypeInformation

3. Save the CSV file and verify the exported contact details.

This file can be used to prepare the contacts for import into Office 365.

Method 2: Import Mail Contacts into Office 365 Using PowerShell

After exporting the contact information, you can bulk-create mail contacts in Exchange Online.

1. Connect to Exchange Online PowerShell.
2. Prepare the CSV file with the required contact details.
3. Run the following command:

Import-Csv "C:\Contacts.csv" | ForEach-Object {

New-MailContact -Name $_.Name `

-DisplayName $_.DisplayName `

-ExternalEmailAddress $_.ExternalEmailAddress `

-FirstName $_.FirstName `

-LastName $_.LastName

}

1. Open the Exchange Admin Center.
2. Navigate to Recipients > Contacts and verify the imported contacts.

This method is useful for migrating multiple mail contacts without creating each one manually.

Method 3: Use an Automated Exchange to Office 365 Migration Tool

For organizations migrating large Exchange environments, manual export and import can become time-consuming. An automated migration solution can help transfer mailbox data and simplify the overall migration process.

The SysTools Exchange to Office 365 Migration Tool supports migrating Exchange mailboxes to Microsoft 365, including associated mailbox data, such as contacts.

The general process involves:

1. Launch the migration tool.
2. Add the source Exchange Server details.
3. Connect the destination Office 365 account.
4. Select the required mailboxes and migration categories.
5. Start the migration and monitor its progress.
6. Verify the migrated data in Office 365.

Before using an automated tool specifically for standalone Exchange mail contact objects, confirm that the required recipient-object migration is supported.

Best Practices Before Migration

• Take a backup of existing mail contacts.
• Check external email addresses before importing.
• Remove or identify duplicate contacts.
• Test the migration with a small contact list.
• Verify the contacts after migration.

Important: In a hybrid Exchange environment, mail contacts synchronized from on-premises Active Directory should generally be managed at the source and synchronized to Microsoft 365 using directory synchronization. Avoid creating duplicate cloud contacts.

Conclusion

Migrating mail contacts from Exchange to Office 365 helps organizations retain important external recipient information. For a small contact list, manual migration may be sufficient, while PowerShell offers a convenient option for bulk imports. For larger Exchange migration projects, consider an automated solution once you confirm its support for the required contact objects.