You have not mentioned the browser you are using? Did you try another browser? Is it just happening in gmail or all websites? If you are using IE, please follow the steps first as given below and in the link http://www.askiyogi.com/internet-internet-programs/5785.html and then http://www.askiyogi.com/internet-internet-programs/18574.html Once the steps are followed, try to open emails in Gmail.
Suggestion 1: Reset Internet Explorer settings
1. Please open Internet Explorer, click "Tools", and click "Internet Options".
2. Switch to the "Advanced" tab.
3. Refer to "Reset Internet Explorer Settings" section, and click "Reset".
4. Click "Close" when the resetting process is complete.
5. Close Internet Explorer and restart it.
Suggestion 2: Run IE without Add-ons
1. Click Start, All Programs, Accessories, System Tools, Internet Explorer (No Add-ons).
2. Visit website in this IE.
Suggestion 3: Try to use the compatibility mode.
Suggestion 4: Click Tools>Options>Advance>disable third party browser extension.
Suggestion 5: Try a Clean Boot
1. Click Start, type MSCONFIG in the Search Bar and Press Enter to start the System Configuration Utility.
2. Click the Services tab, check the Hide All Microsoft Services box and click Disable All (if it is not gray).
3. Click the Startup tab, click Disable All and click OK.
4. Restart the computer and test the issue.
Please monitor the system in the Clean Boot environment. If the problem does not occur, it indicates that the problem is related to one application or service we have disabled. You may use the MSCONFIG tool again to re-enable the disabled item one by one to narrow down the problem.
Here’s to Good Karma