Topic says it all 
1.) First, go to google Documents page from google main page or visit docs.google.com
2.) Then login to your account with Google ID
3.) Go to New>> Document
4.) There Click on Insert>> Image
5.) you'll get a window like below where you can insert the desired external link or else you can upload a picture of your own from yo pc.
Insert the link and and click Insert
6.) You'll see the image shown in the document
7.) right click on the image and then copy
8.) Go to Gmail or whatever your webmail service and paste the image on composing field
9.) You will see the image is shown in the composing new mail
Tested on Gmail , Yahoo and hotmail so seems like it's working almost on every webmail service
BTW sorry if this is a repost
1.) First, go to google Documents page from google main page or visit docs.google.com
2.) Then login to your account with Google ID
3.) Go to New>> Document
4.) There Click on Insert>> Image
5.) you'll get a window like below where you can insert the desired external link or else you can upload a picture of your own from yo pc.
Insert the link and and click Insert
6.) You'll see the image shown in the document
7.) right click on the image and then copy
8.) Go to Gmail or whatever your webmail service and paste the image on composing field
9.) You will see the image is shown in the composing new mail
Tested on Gmail , Yahoo and hotmail so seems like it's working almost on every webmail service
BTW sorry if this is a repost
