Fixed booleans support

Dockerfile

@@ -56,7 +56,7 @@ ENV BIFF=no \
     DKIM_CANONICALIZATION=simple \
     # To support multiple concurrent public keys per sending domain, the DNS namespace is further subdivided with "selectors". Selectors are arbitrary names below the "_domainkey." namespace. For example, selectors may indicate the names of your server locations (e.g., "mta1", "mta2", and "mta2"), the signing date (e.g., "january2005", "february2005", etc.), or even the individual user.
     DKIM_SELECTOR=mail \
-    # /etc/aliases entries
+    # /etc/aliases entries @todo: Better examples there
     ALIASES=
 
 ADD ./container-files/relay-setup-entrypoint.sh /usr/local/bin/relay-setup-entrypoint.sh

README.md

@@ -148,7 +148,7 @@ List of all environment variables that could be used.
 # To support multiple concurrent public keys per sending domain, the DNS namespace is further subdivided with "selectors". Selectors are arbitrary names below the "_domainkey." namespace. For example, selectors may indicate the names of your server locations (e.g., "mta1", "mta2", and "mta2"), the signing date (e.g., "january2005", "february2005", etc.), or even the individual user.
 - DKIM_SELECTOR # (example value: mail)
 
-# /etc/aliases entries
+# /etc/aliases entries @todo: Better examples there
 - ALIASES # (example value: )
 
 

container-files/templates/etc/supervisor/supervisord.conf.j2

@@ -24,7 +24,7 @@ command=rsyslogd -n
 stdout_events_enabled=true
 stderr_events_enabled=true
 
-{% if ENABLE_DKIM == 'true' %}
+{% if ENABLE_DKIM.lower() == 'yes' or ENABLE_DKIM.lower() == 'true' %}
 [program:opendkim]
 command=opendkim -x /etc/opendkim.conf -A -f
 stdout_events_enabled=true