Comment 6 for bug 2054908

Steve - it is a server package for hosting a web key server, it's entirely reasonable for it to depend on a mail transport agent. A WKS server, upon uploading a key, sends confirmation emails to the UIDs in the key, before publishing it, so that it only published keys with consent.

It's problematic that it was installed by default, and I'm fixing this here and in Debian by doing the restructuring I did. This is not optimal for people upgrading without quirks (i.e. Debian users especially) but I don't think breaking the wks server to make upgrades without quirks nicer is a better choice.