Which cmdlet is used to create a new branding template with an expiration date of seven days?

The cmdlet used to create a new branding template with an expiration date of seven days is New-OMEConfiguration. This cmdlet is specifically designed to configure settings related to Office Message Encryption (OME), including the creation of branding templates that can control characteristics such as expiration for encrypted messages. When establishing a branding template, the cmdlet allows administrators to set various parameters, including the duration before which the message will expire, making it ideal for creating short-term branding options.

Other options are focused on different functionalities within Microsoft 365. Set-OMEConfiguration is used to modify existing settings rather than creating new templates. Get-TransportRule is intended for retrieving information about transport rules in Exchange Online and does not pertain to branding templates. New-Mailbox is used to create new mailboxes in Exchange Online, which is unrelated to the configuration of encryption branding templates.