Users experiencing long delays while opening large e-mail messages through Outlook. A popup window opens as Outlook continues to download the entire message as shown in screenshot below.
If you're using Microsoft Online Services, Exchange Online or another hosted Exchange provider, your default Outlook settings might be set to "Download Headers and then Full Items" or "Download Headers" only. By setting the cached mode to "Download Full Items", Outlook will download the entire message in the background prior to appearing in user's inbox.
In the bottom right hand corner of your Microsoft Outlook application you will see "Connected to Microsoft Exchange (Headers)". If you see this text, Exchange cached mode is downloading the message headers, the message appears in the inbox, and then the full message details are downloaded. If you would like to change these settings so that users only receive an email notification once the message has fully downloaded, then click on the "Connected to Microsoft Exchange" text and select the "Download Full Items" option as shown in the screenshot above. This can often be a major factor in improving the user experience.
TechNote Published By: INFINIT Consulting
*INFINIT TechNotes are provided solely for recommendation purposes and may not resolve each unique case. INFINIT Consulting will not be held liable for any issues arising from implementing the recommendations provided in this documentation.