Comment 46 for bug 1519331

The reason for it not being released for zesty before was that it seemed to have 3 undefined autopkgtest failures for sbuild. After looking into those now, it seems that the sbuild autopkgtests seem to be constantly failing for those 3 archs for all packages - so, (most likely) unrelated to the postfix upload. I would say that's enough for me to get it released.

On it now.