Still a workaround for dovecot from alpine:edge

dovecot/Dockerfile

@@ -6,7 +6,10 @@ RUN echo "@testing http://nl.alpinelinux.org/alpine/edge/testing" >> /etc/apk/re
      dovecot-sqlite \
      dovecot-pigeonhole-plugin \
      dovecot-antispam-plugin@testing \
- && rm -rf /var/cache/apk/*
+     spamassassin \
+     bash \
+ && rm -rf /var/cache/apk/* \
+ && sed -i 's,90:65533,90:12,' /etc/passwd
 
 COPY dovecot-pigeonhole-plugin-extdata-39-r0.apk /
 RUN apk add --allow-untrusted --force dovecot-pigeonhole-plugin-extdata-39-r0.apk