The sidebar patch is no longer included in the brew recipe, which sucks.
You can grab the newest patches here: http://www.lunar-linux.org/mutt-sidebar/
Here is how to edit brew to apply the patch without errors:
brew edit mutt
- add
option "with-sidebar-patch", "Apply sidebar patch
- add:
patch do
url "http://lunar-linux.org/~tchan/mutt/patch-1.5.24.sidebar.20150917.txt"
end if build.with? "sidebar-patch"
- remove current version of mutt
- run
brew install --with-s-lang --with-sidebar-patch
Also launchd is stupid, so I just used automater to create Applications/fetchmail.app
you must export when creating the above
And have it automatically start when logging in