Always host images on your website instead of embedding them in messages. Some email providers filter email with embedded images. File size can get quite large with multiple embedded images, which can also get the message blocked.
Instead, host those images on your website and make sure all paths point to the full URL. Always use absolute links (http://www.mysite.com/images) instead of relative links (“images\image.gif”) and make sure the path does not contain spacing or “%20” HTML code. Image links with spacing in them will not be displayed properly in Gmail and Lotus Notes mail accounts. These email clients will replace your image with a red cross and disturb the lay-out of your email message. Also, make sure that the images will remain on the server for several weeks, recipients might file your email to read them at a later stage.
Tip: never link to your images by using the IP address of your server (e.g: http://22.214.171.124/image.gif) because it will trigger certain spam filters to block your emails.
Be aware of the file-size of the images in your HTML emails. Do not use the “height” and “width” parameters to resize big images because it will not reduce the file-size of the image. If you need to resize or crop images, always use image-processing software to do this.