When you use Outlook on a mobile device connected to a cellular network, the app may download only email headers instead of the full message content. This behavior is controlled by the “Show Headers Only” preference, which is designed to reduce data usage. The setting can cause confusion because messages appear incomplete or require a manual download to read the body. This article explains where this setting is located and provides the exact steps to disable it so you receive full email content over cellular connections.
Key Takeaways: Disabling Show Headers Only in Outlook Mobile
- Outlook Mobile Settings > Show Headers Only toggle: Turn this off to download full messages over cellular networks.
- Outlook Mobile Settings > Download Full Content: Overrides the Show Headers Only setting for individual email accounts.
- Data usage warning: Disabling this feature increases cellular data consumption for email downloads.
Understanding the Show Headers Only Cellular Download Preference
The Show Headers Only preference is a data-saving feature in the Outlook mobile app for iOS and Android. When enabled, Outlook downloads only the sender, subject, and a portion of the message preview while on a cellular connection. The full message body and attachments remain on the server until you tap the message to download them manually.
This setting is separate from the standard Sync Settings that control how often Outlook checks for new mail. It applies exclusively to cellular data connections and does not affect Wi-Fi downloads. The feature is controlled by a single toggle in the Outlook mobile settings, but it can also be overridden per email account.
Understanding this distinction is important because users often mistake the Show Headers Only behavior for a sync problem or a corrupted mailbox. The root cause is simply a user-configurable preference designed to conserve mobile data. Once you disable it, Outlook will download the complete message content automatically over any cellular network.
Steps to Disable Show Headers Only in Outlook Mobile
The following steps apply to the official Outlook app on iOS and Android. The interface is nearly identical on both platforms.
- Open the Outlook app and go to Settings
Tap your profile picture or the account icon in the top left corner of the main screen. Scroll down and tap the gear icon labeled Settings. - Select the Mail section
In the Settings menu, tap Mail. This section contains all email sync and download preferences. - Locate the Show Headers Only toggle
Scroll down to the Downloading Content section. You will see a switch labeled Show Headers Only. If the switch is blue or green, the feature is currently enabled. - Disable the Show Headers Only toggle
Tap the switch so it turns gray or white. This disables the feature for all email accounts in the app. - Verify the change
Return to the inbox and force a manual sync by pulling down on the message list. Open a recent email that previously showed only headers. The full message body should now appear without requiring a manual download.
Override Show Headers Only for a Single Account
If you want to keep the global setting enabled but allow full content for one specific account, use the per-account download preference.
- Open Settings and tap your account
In Settings, tap the email account you want to modify. The account appears under the Accounts section. - Change the Download Full Content option
Under the account settings, tap Download Full Content. Select the option that matches your preference: Always, On Wi-Fi Only, or Off. Choosing Always overrides the global Show Headers Only setting for that account. - Confirm the override
Exit settings and test the account by opening a message while on a cellular connection. The full content should load automatically.
What Happens After Disabling Show Headers Only
Once you disable Show Headers Only, Outlook will download the complete email body and any inline images over cellular networks. Attachments are not automatically downloaded unless you also enable the Download Attachments option in the same settings section. This distinction is important because large attachments can quickly consume your data plan.
If you later decide to re-enable the feature, follow the same steps and turn the toggle back on. The setting is not permanent and can be changed at any time without affecting your email account or server settings.
If Outlook Still Shows Only Headers After Disabling the Setting
Outlook Mobile Still Shows Only Headers on Cellular
If you disabled the toggle but Outlook continues to show only headers, check the per-account download preference. An account set to Download Full Content Off will override the global setting. Open Settings > tap the affected account > Download Full Content and set it to Always.
Outlook Shows Only Headers on Wi-Fi
The Show Headers Only setting applies only to cellular connections. If you see only headers on Wi-Fi, the issue is not related to this preference. Check your Wi-Fi connection, server settings, or try removing and re-adding the email account.
Messages Downloaded as Headers After an App Update
A recent Outlook app update may have reset your preferences. Open Settings > Mail > Downloading Content and verify the Show Headers Only toggle is still off. If it was re-enabled, turn it off again.
Show Headers Only vs Full Content Download: Key Differences
| Item | Show Headers Only (On) | Show Headers Only (Off) |
|---|---|---|
| Data usage over cellular | Low — only header text is downloaded | Higher — full message body and inline images are downloaded |
| Message appearance | Shows sender, subject, and first few lines of preview | Shows the complete message body immediately |
| Manual action needed | Tap each message to download full content | No manual action required |
| Attachment behavior | Not downloaded until you tap the attachment | Not downloaded automatically — controlled by separate setting |
| Applicable network | Cellular only | All networks (cellular and Wi-Fi) |
The main trade-off is data consumption versus convenience. With Show Headers Only enabled, you save cellular data but must tap each message to see its full content. Disabling the feature provides a seamless reading experience at the cost of higher data usage.
You can now disable the Show Headers Only cellular download preference in Outlook mobile and control how much data your email consumes. To further reduce data usage without sacrificing full content, consider enabling the Download Attachments option only on Wi-Fi. For advanced control, use the per-account Download Full Content setting to allow full downloads for critical accounts while keeping headers for others.