Thunderbird:
Enter = new paragraph
Ctrl + Enter = send message
Shift + Enter = newline in the same paragraph (mindblown)
@peterbabic oh, you are referring to *html* mode. It took me a while to understand what Shift+ENTER did, since by default I use *text* mode 🙂
@peterbabic
To be fair, setting plain text is the first thing I do on every mail client I touch. After that, you can still use HTML by holding the shift key while clicking on reply or compose.
@aluaces I somehow failed to change any defaults in Thunderbird so far 😃