Enable-MailUser

The Alias parameter specifies the Exchange alias (also known as the mail nickname) for the recipient. This value identifies the recipient as a mail-enabled object, and shouldn't be confused with multiple email addresses for the same recipient (also known as proxy addresses). A recipient can have only one Alias value. The maximum length is 64 characters.

The Alias value can contain letters, numbers and the following characters:

• !, #, %, *, +, -, /, =, ?, ^, _, and ~.
• $, &, ', `, {, }, and | need to be escaped (for example -Alias what`'snew) or the entire value enclosed in single quotation marks (for example, -Alias 'what'snew'). The & character is not supported in the Alias value for Microsoft Entra Connect synchronization.
• Periods (.) must be surrounded by other valid characters (for example, help.desk).
• Unicode characters U+00A1 to U+00FF.

When you create a recipient without specifying an email address, the Alias value you specify is used to generate the primary email address (alias@domain). Supported Unicode characters are mapped to best-fit US-ASCII text characters. For example, U+00F6 (ö) is changed to oe in the primary email address.

If you don't use the Alias parameter when you create a recipient, the value of a different required parameter is used for the Alias property value:

• Recipients with user accounts (for example, user mailboxes, and mail users): The left side of the MicrosoftOnlineServicesID or UserPrincipalName parameter is used. For example, [email protected] results in the Alias property value helpdesk.
• Recipients without user accounts (for example, room mailboxes, mail contacts, and distribution groups): The value of the Name parameter is used. Spaces are removed and unsupported characters are converted to question marks (?).

If you modify the Alias value of an existing recipient, the primary email address is automatically updated only in environments where the recipient is subject to email address policies (the EmailAddressPolicyEnabled property is True for the recipient).

The Alias parameter never generates or updates the primary email address of a mail contact or a mail user.

The Confirm switch specifies whether to show or hide the confirmation prompt. How this switch affects the cmdlet depends on if the cmdlet requires confirmation before proceeding.

• Destructive cmdlets (for example, Remove-* cmdlets) have a built-in pause that forces you to acknowledge the command before proceeding. For these cmdlets, you can skip the confirmation prompt by using this exact syntax: -Confirm:$false.
• Most other cmdlets (for example, New-* and Set-* cmdlets) don't have a built-in pause. For these cmdlets, specifying the Confirm switch without a value introduces a pause that forces you acknowledge the command before proceeding.

The DisplayName parameter specifies the display name of the mail user. The display name is visible in the Exchange admin center and in address lists. The maximum length is 256 characters. If the value contains spaces, enclose the value in quotation marks (").

The DomainController parameter specifies the domain controller that's used by this cmdlet to read data from or write data to Active Directory. You identify the domain controller by its fully qualified domain name (FQDN). For example, dc01.contoso.com.

The ExternalEmailAddress parameter specifies an email address outside the organization. Email messages sent to the mail-enabled user are sent to this external address.

The Identity parameter specifies the user that you want to mail-enable. You can use any value that uniquely identifies the user. For example:

• Name
• Distinguished name (DN)
• Canonical DN
• GUID

The MacAttachmentFormat parameter specifies the Apple Macintosh operating system attachment format to use for messages sent to the mail contact or mail user. Valid values are:

• BinHex (This is the default value)
• UuEncode
• AppleSingle
• AppleDouble

The MacAttachmentFormat and MessageFormat parameters are interdependent:

• MessageFormat is Text: MacAttachmentFormat can be BinHex or UuEncode.
• MessageFormat is Mime: MacAttachmentFormat can be BinHex, AppleSingle or AppleDouble.

The MessageBodyFormat parameter specifies the message body format for messages sent to the mail contact or mail user. Valid values are:

• Text
• Html
• TextAndHtml (This is the default value)

The MessageFormat and MessageBodyFormat parameters are interdependent:

• MessageFormat is Mime: MessageBodyFormat can be Text, Html or TextAndHtml.
• MessageFormat is Text: MessageBodyFormat can only be Text.

The MessageFormat parameter specifies the message format for messages sent to the mail contact or mail user. Valid values are:

• Text
• Mime (This is the default value)

The MessageFormat and MessageBodyFormat parameters are interdependent:

• MessageFormat is Mime: MessageBodyFormat can be Text, Html or TextAndHtml.
• MessageFormat is Text: MessageBodyFormat can only be Text.

Therefore, if you want to change the MessageFormat parameter from Mime to Text, you must also change the MessageBodyFormat parameter to Text.

The PrimarySmtpAddress parameter specifies the primary return email address that's used for the recipient.

By default, the primary address is the same as the ExternalEmailAddress parameter value.

If you use the PrimarySmtpAddress parameter to specify the primary email address, the command sets the EmailAddressPolicyEnabled property of the mail user to False, which means the email addresses of the mail user aren't automatically updated by email address policies. We recommend that you don't set the primary email address to a value other than the ExternalEmailAddress unless you're in a cross-forest scenario.

The UsePreferMessageFormat specifies whether the message format settings configured for the mail user or mail contact override the global settings configured for the remote domain or configured by the message sender. Valid value are:

• $true: Messages sent to the mail user or mail contact use the message format that's configured for the mail user or mail contact.
• $false: Messages sent to the mail user or mail contact use the message format that's configured for the remote domain (the default remote domain or a specific remote domain) or configured by the message sender. This is the default value.

The WhatIf switch simulates the actions of the command. You can use this switch to view the changes that would occur without actually applying those changes. You don't need to specify a value with this switch.