To send images by email, you must configure ViewNResize using the "Tools - Preferences - Mail settings" menu entry.
If you don't know what your SMTP server is, you need to ask your internet service provider. Prior to doing that, have a look in your papers, it must be written there somewhere.
Once this is done, if you just want to send the current image, simply click on the toolbar button
, write the email address of the person you want to send it to in the "To:" field and click on the "Send email" button.
If you want to send multiple images, you need to use the picture basket.
Once all the pictures you want to send are in the basket, click on the "Basket - Send content by email" menu entry. You can also do that from the picture basket. Then, you still have the option to uncheck the pictures you don't really want to send by double-clicking on their names.