setting and saving font size
For sending emails, I want to be able to save the font size I choose (14), so that I don't have to re-set it each time I am writing. I know how to change the font size, but can't save it. How do I keep the font size?
Alla svar (3)
That size is 14 pixels, not a windows style 14 points, so it is about 30% smaller that it's points equivalent, but on say really high resolution monitors it may be much smaller. Seriously the default is the most compatible with with various devices as it works with the normal smaller bigger that HTML in web pages uses to scale for devices.
On the toolbar 
> Options > composition > General for compose font options
Thanks for the answer, but it didn't help solve my problem. I have moved my old aol email to firefox, and the font size that I had customized on aol does not transfer apparently. I'm still trying to find a way to avoid having to re-set the font every time I send or reply to an email. It's not a big problem, but is a bit annoying.
So is this really a question about Firefox and not Thunderbird?
If it is Thunderbird, the best advice is to leave the composition font at the default, and adjust your display font size to suit you. The font size that suits you may not be the best for your correspondents.