Hi,
I've just uploaded GeanySendMail 0.4.4 onto server, which is an maintenance release of 0.4 series. These should working with Geany 0.18 and only including a minor update in terms of code: Now its possible to just acknowledge the entered email address by hitting return.
But more important is that GeanySendMail main development will now also be done direct inside the combined geany-plugins tree in favor of just merging release into this tree. With this change the version number of next release will most likely be something around 0.19 ;)
However, latest updates you can fine if you like at http://frank.uvena.de/en/Geany/geanysendmail/
Happy coding, Frank