diff --git a/core/admin/mailu/internal/nginx.py b/core/admin/mailu/internal/nginx.py
index fa127584..1e0b16c2 100644
--- a/core/admin/mailu/internal/nginx.py
+++ b/core/admin/mailu/internal/nginx.py
@@ -84,7 +84,7 @@ def get_status(protocol, status):
     return status, codes[protocol]
 
 def extract_host_port(host_and_port, default_port):
-    host, _, port = re.match('^(.*)(:([0-9]*))?$', host_and_port).groups()
+    host, _, port = re.match('^(.*?)(:([0-9]*))?$', host_and_port).groups()
     return host, int(port) if port else default_port
 
 def get_server(protocol, authenticated=False):
diff --git a/optional/fetchmail/fetchmail.py b/optional/fetchmail/fetchmail.py
index 98b61c4c..4be3c2bd 100755
--- a/optional/fetchmail/fetchmail.py
+++ b/optional/fetchmail/fetchmail.py
@@ -28,7 +28,7 @@ poll "{host}" proto {protocol}  port {port}
 
 
 def extract_host_port(host_and_port, default_port):
-    host, _, port = re.match('^(.*)(:([0-9]*))?$', host_and_port).groups()
+    host, _, port = re.match('^(.*?)(:([0-9]*))?$', host_and_port).groups()
     return host, int(port) if port else default_port
 
 
diff --git a/setup/templates/macros.html b/setup/templates/macros.html
index 4af20c4e..17cef872 100644
--- a/setup/templates/macros.html
+++ b/setup/templates/macros.html
@@ -12,7 +12,7 @@
 {% macro radio(name, value, emph, text, current) %}
   <div class="radio">
     <label>
-      <input type="radio" name="{{ name }}" value="{{ value }}"{% if current == value %} checked="checked"{% endif %}>
+      <input type="radio" name="{{ name }}" value="{{ value }}"{% if current == value %} checked="checked"{% endif %} required="required">
       {% if emph %}
       <strong>{{ emph }}</strong>,
       {% endif %}
diff --git a/towncrier/newsfragments/1669.bugfix b/towncrier/newsfragments/1669.bugfix
new file mode 100644
index 00000000..7409b2d2
--- /dev/null
+++ b/towncrier/newsfragments/1669.bugfix
@@ -0,0 +1 @@
+Fix "extract_host_port" function to support containers with custom / dynamic ports