http://www.imapwiki.org/ImapTest

Cassandane has support for the ImapTest engine.  First you need to build
imaptest, which isn't too hard - download and build dovecot (it can just
sit in the build target, it doesn't need to be installed) and then
download and build imaptest.  I used mercurial and downloaded the latest
of both.

Then add this block to your cassandane.ini:

---

[imaptest]
basedir=/home/brong/src/imaptest/imaptest
suppress=append-binary fetch-binary-mime fetch-binary-mime-base64 fetch-binary-mime-qp urlauth-binary

---

I'm hoping to fix these!  There are also some tests that don't run because
we don't advertise the capabilities, and I'd like to fix those as well.

Finally, we should contribute tests back to ImapTest if they are generic
tests that we think would be valuable for other servers.