Campaign images should be uploaded close to the recommended specification. For images that go the full width of an email campaign, an image should not exceed 600px. For an image that will take up a half a campaign, the image should not exceed 270px width. GIFs up to 5mp can be uploaded and should follow the same dimension specifications as other images.
The Why: For most ISPs (Gmail, Yahoo, AOL), the default to image rendering will be defined within the HTML template. That, however, isn’t the case for email clients like Outlook. The image, by default within Outlook, will attempt to render as close to original specification as possible. If an image is uploaded exceeding the suggested width, then a sender can expect to encounter rendering issues related to B2B mail clients.
How to Test: The easiest way to test in within your Revinate Account! Under the Preview section, within an email template, you can find various Outlook related renderings. These renderings will display where the message will potentially be displayed incorrectly within the related Email Clients.