I HAVE done this before. But I can't remember what I used, and right now the editors I have that know about html are including
- <img src="filename" ...
- <img src="data:image/*;base64,...
The latter style works. The former, for some reason, doesn't.
I'm quite sure I could dig around and find an encoder and amend the code. But I'm lazy, and I'd rather find out either how to make the first style work, or a wysiwyg-type html editor that will look after things like Thunderbird-compatible html email sigs without having all the extra stuff you need to make websites.
(I'm completely sure that I've missed something terribly obvious, somewhere. But I know, every time I've had to do something like this -- and you can probably tell that it doesn't exactly happen very frequently -- I've had to jump through the same set of hoops and failed to make a note of what I did for next time!)
Any helpful advice gratefully appreciated! (Well, almost any. "Encode your graphic and stop being lazy"-type answers will attract derision and may even encourage me to find out how to email a rotten egg smell.)
Okay, so nobody actually wanted to say it...
I've dug a bit deeper. If I do the Recommended Thing -- basically, make a new email with TB, design away until I have something that looks right, then save it as html, sometimes it works.
But some of the time things go Weird. Like odd shifts of paragraph style, without any obvious way to put them back again. I've assumed that Thunderbird's documented preferences for simple html over "original" html are for better reasons than just processing oomph.
It annoys me that I seem to have to use TB itself to generate these files to have much chance of success -- albeit only about 70% if I'm trying to be too clever -- but that I can't edit TB-generated files inside TB.
Oh, and TB uses file links, not base64-encoded stuff. (I still can't work out what I did to make that happen last time round, a couple of years back.) And sometimes it just shows an outline where the graphic should have been, and more often than not attempts to make the graphic come out at exactly the right size -- in comparison to the text -- fail miserably too.
I wish they'd let me go back to sending plaintext emails.