| On-premises Active Directory attribute name | Example On-premises Active Directory attribute value | Example Exchange Online email addresses |
| proxyAddresses | SMTP:user1@contoso.com |
Primary SMTP: user1@contoso.com Secondary SMTP: user@contoso.onmicrosoft.com |
| proxyAddresses | smtp:user1@contoso.com | Primary SMTP: user@contoso.onmicrosoft.com Secondary SMTP: user1@contoso.com |
| proxyAddresses | SMTP:user1@contoso.com smtp:user1@sub.contoso.com |
Primary SMTP: user1@contoso.com Secondary SMTP: user@sub.contoso.com Secondary SMTP: user@contoso.onmicrosoft.com |
| User1@contoso.com |
Primary SMTP: user1@contoso.com Secondary SMTP: user@contoso.onmicrosoft.com |
|
| UserPrinicpalName | User1@contoso.com |
Primary SMTP: user1@contoso.com Secondary SMTP: user@contoso.onmicrosoft.com |