If I type the name of a website, highlight it and click Insert > Link, then paste the link into the Link Location box, then click OK, when I then try to continue the sentence in the draft email, what I type becomes part of the blue underlined link text. This also seems to happen when I type the name of website direct into Link Text box, but not always. Sometimes I can achieve a workaround by starting a new paragraph, and then deleting the paragraph to get the text back to where I want it, but this doesn't always work. This has been bothering me through several iterations of Thunderbird, and I keep hoping the next download will fix it!

Windows 7, Thunderbird 45.7.0