Why my website e-mail goes in spam or images doesn't show up in people mailboxes ?

I send newsletter to all the members of my website, usually i just create simple newsletter with text and hyperlinks

So many times i tried adding images to it but whenever i add images in the newsletter e-mail, the users who are using different mailboxes, either my mail goes in their SPAM folder or if my mail goes in their INBOX then image doesn't show up, it shows a blank space

what's the issue ? what's causing the issue ? code ? How to solve this issue ?

Almost everyday we recieve newsletters from many websites/companies (there newsletter includes images, colors full templates etc) and still we recieve in our inbox and all the images are visible. how ?

The is the result if i try to include images in the body of e-mail using Fckeditor.

(gmail : image doesn't show up except blank space; yahoo - images blocked/in SPAM, hotmail-no image, aol - block images, outlook - 50% success 50% no image)

Method that i use to upload image in the body of e-mail (Use Image tool provided by Fckeditor : Use a link of image which i uploaded on the internet)

(I have also tried to upload image which i uploaded on my server too , that also didn't work)

Ok to test my server i tested it by sending a picture/image through e-mail , i linked the e-mail with the image, and in my mailbox i check the image, it was being displayed perfectly fine in all the mailboxes.

I guess there is some problem with the Fckeditor that prevents any image to send in different mailboxes of make it as spam or doesn't display the image.

Any solution ?????