Use lean popouts to reduce memory used when reading mail messages
This article contains information for improving message download performance in Outlook on the web. This article is part of the Network planning and performance tuning for Office 365 project.
As an Office 365 global administrator, you can configure Outlook on the web to deliver lean popouts, a smaller, less memory-intensive version of certain email messages in Microsoft Edge or Internet Explorer. When lean popouts are configured for Outlook on the web, server-side rendered components are loaded that optimize performance.
As of March 2018, lean popouts are not available for messages that specify usage rights restrictions, such as Information Rights Management (IRM).
These features will continue to work in the main window but are not available in lean popouts:
Skype for Business presence
To configure lean popouts for all users within your Office 365 organization
Run the Set-OrganizationConfig cmdlet with the LeanPopoutEnabled parameter as follows:
Set-OrganizationConfig -LeanPopoutEnabled <$true |$false >
For example, to enable lean popouts for all users in your organization:
Set-OrganizationConfig -LeanPopoutEnabled $true
To disable lean popouts for all users in your organization:
Set-OrganizationConfig -LeanPopoutEnabled $false