The Outlook PC environment does not support max-width as an HTML property. Due to this limitation, when a 300×250 creative size serves with a template width value, it causes the 300×250 creative to expand to the same aspect ratio of the template width value being used. This ONLY occurs when the email is viewed in the Outlook AND PC email environment.

EXAMPLE: If a template width value of 600px is being used, then the 300×250 creative will expand to a 600×500 image.

Outlook PC environment definition: Outlook PC Environment refers to email opens that occur in Outlook (email client) AND on a PC (device). Outlook Mobile DOES NOT classify as Outlook PC and DOES NOT have the expansion issue.

Unfortunately, this is a limitation of Outlook and beyond LiveIntent’s control to address. To prevent 300×250 creatives from expanding to the template width, LiveIntent does not serve a 300×250 creatives in the Outlook PC environment.

If you have a guaranteed direct-sold campaign ONLY serving a 300×250 creative, the campaign will not serve in the Outlook PC environment. 300×250 creative in the Outlook PC environment will either:

1. serve a non-300×250 creative from the LiveIntent Exchange (if exchange demand is enabled).
2. serve a non-300×250 creative size from a different direct-sold campaign you have trafficked.
3. or collapse to an invisible pixel if there is no eligible demand.

In order to ensure your client’s ad serves across all environments, please proceed with one of the following solutions:

Recommended Best Practice

Traffic multiple creative sizes 

Trafficking multiple creative sizes will allow a non-300×250 creative to serve in the Outlook PC environment when the 300×250 creative cannot.

• LiveIntent recommends trafficking 300×250, 970×250, and 970×550 creative sizes for all direct-sold campaigns, but please consult your account manager to ensure these sizes make the most sense for your needs.
• If your advertiser does not have a 970×250 or 970×550 creative asset, LiveIntent’s Creative Services team can provide assistance. 

PLEASE NOTE: Trafficking the 970×250 and 970×550 creative sizes will allow them to serve across ALL email environments with the 300×250 creative size.

Alternative Option

Traffic a non-300×250 creative size for the Outlook PC environment ONLY
If you are unable to traffic the 970×250 and 970×550 sizes in all environments, you can isolate the Outlook PC environment by targeting it with a non-300×250 creative size utilizing priority levels. This will allow the 300×250 creative size to serve in every other email environment. This option requires you to traffic two line items:

1. 1. 1. Create a guaranteed direct-sold line item with a 300×250 creative set to priority 1.
      2. Create a second guaranteed direct-sold line item with a non-300×250 creative size (i.e. 970×250, 970×550) set to priority 2.

Because the line item for the 300×250 creative is set at priority 1, this creative will serve first in ALL environments EXCEPT Outlook PC. Since the 300×250 creative will not serve in Outlook PC, the priority 2 will target the Outlook PC environment and serve the non-300×250 creative. For more details on priority levels for direct-sold campaigns, please refer to this article. 

NOTE: Ensure there are no other campaigns with the same priority level targeting this inventory, otherwise those campaigns will also have the opportunity to serve.