Be careful with old versions!
These versions are displayed for reference and testing purposes. You should always use the latest version of an add-on.
Some Websites/Webmails (e.g. GMX) use for their mail portal other(!) domains - hidden to the user. I still try to figure out how I can handle this correctly - therefore you have to switch off sometimes BM. If any of you have an idea, mail me - you will be mentioned as developer/contributor :-)