Well, Windows Live Writer doesn't offer this by default, but it can be done.
And there's not a plug-in I know of that addresses this issue either...
So here’s the instructions on how to do it, plus check out the extra options you can tack on by using the MAILTO option…
Open Windows Live Writer, do a new post, or open a pre-existing one.
Paste the image, then double-click on it to bring up the edit options for it.
Choose the option to LINK TO, WEB ADDRESS.
Then enter the eMail address you want to link the image to..
Click OK. Done.
So, now you can test it...
In Windows Live Writer, at the bottom, choose PREVIEW.
Just click on the image, and the default eMail client should open.
I tested this with Thunderbird on my machine, but this command is standard, so it should work with any eMail client.
But Go Bigger.
Now, if you want to get fancy, you can add a SUBJECT [or more] to the eMail when it's created; thanks to Windows Live Writer just being a basic HTML editor.
You can change the link to read like this...
mailto:email@example.comfirstname.lastname@example.orgemail@example.com&subject=Comments about the color blue&body=The following is everything I have to say about the color blue.
This will create an email with CC and BCC and a prefilled subject and a body...
I hope this helps…
Larry Henry Jr.