Pictures blocked
By default most of the email client block the picture to view from the email panel on the users email account. If you want to edit the setting about wheather you want to open or close the pictures of email then you need to manage those setting on email client such as outlook manually.
Here are the steps which is used to manage the email's picture on outlook, at which you define wheather you need to open or stop the pictures on email.
- Open Microsoft Outlook and goto "Tools" option.
- In the Tools option select "Trust Center" With this a new pop up window wil open.

Download Pictures option in outlook
- Now in the trust center select "Automatic Download" tab.
- In the automatic download tab manage your picture wheather you want to view them automatically or you want to close them.
That is how you can edit the settings of picture to open or stop in outlook if the picture has been blocked.
Now the point is this why you have got a blocked piture on your email with email clients. Here when we use email clients they have such type of algorithms build to detect wheather the image is remote image or the proper image. If the email client or email provider think that the image is not proper and looks like remote image or remote picture then they block the picture to protect the email account. Because with remote images email sender can capture some information regarding to your email account or computer.
With remote picture email sender send you the image which have some hard coding include as you give them permission to download to your computer so they can get the information which were saved on cookies or hard drive. While the image or remote picture are downloading at the same time the information your computer has been going to the email sender email address via email or any other source.
Those are some of the points which you have to consider if you are giving permission to download those block pictures on your computer.