diff --git a/mbox2web b/mbox2web
index d5d48dd..19c4f7a 100755
--- a/mbox2web
+++ b/mbox2web
@@ -74,26 +74,30 @@ def save_part(msg, disposition):
     os.makedirs("parts", exist_ok=True)
     with open("parts/" + filename, "wb") as fh:
         fh.write(payload)
-    template_name = disposition + "_" + content_type.replace("/", "_") + ".html"
-    bodytmpl = jenv.get_template(template_name)
-    context = {
-        "name": name,
-        "url": "../../parts/" + filename,
-    }
-    bodyhtml = bodytmpl.render(context)
-    return bodyhtml
+    url = "../../parts/" + filename
+    if disposition == "_url":
+        return url
+    else:
+        template_name = disposition + "_" + content_type.replace("/", "_") + ".html"
+        bodytmpl = jenv.get_template(template_name)
+        context = {
+            "name": name,
+            "url": url,
+        }
+        bodyhtml = bodytmpl.render(context)
+        return bodyhtml
 
 
 partial_message_cache = {}
 
-def render_body(msg):
-    def render_text_plain(msg):
+def render_body(msg, extra=None):
+    def render_text_plain(msg, extra=None):
         bodytmpl = jenv.get_template("body_text_plain.html")
         context = {
             "body": msg.get_payload(decode=True).decode(msg.get_charset() or "iso-8859-1")
         }
         return bodytmpl.render(context)
-    def render_multipart_mixed(msg):
+    def render_multipart_mixed(msg, extra=None):
         parts = msg.get_payload()
         if type(parts) == str:
             # mislabelled, assume text/plain
@@ -106,7 +110,7 @@ def render_body(msg):
             "parts": partshtml
         }
         return bodytmpl.render(context)
-    def render_multipart_digest(msg):
+    def render_multipart_digest(msg, extra=None):
         partshtml = []
         for part in msg.get_payload():
             partshtml.append(render_message(part))
@@ -115,7 +119,7 @@ def render_body(msg):
             "parts": partshtml
         }
         return bodytmpl.render(context)
-    def render_message_rfc822(msg):
+    def render_message_rfc822(msg, extra=None):
         partshtml = []
         for part in msg.get_payload():
             partshtml.append(render_message(part))
@@ -124,15 +128,15 @@ def render_body(msg):
             "parts": partshtml
         }
         return bodytmpl.render(context)
-    def render_text_html(msg):
-        htmlpart = HTMLPart()
+    def render_text_html(msg, extra=None):
+        htmlpart = HTMLPart(extra)
         htmlpart.feed(msg.get_payload(decode=True).decode(msg.get_charset() or "iso-8859-1"))
         bodytmpl = jenv.get_template("body_text_html.html")
         context = {
             "body": jinja2.Markup(htmlpart.as_string())
         }
         return bodytmpl.render(context)
-    def render_text_enriched(msg):
+    def render_text_enriched(msg, extra=None):
         payload = msg.get_payload(decode=True).decode(msg.get_charset() or "iso-8859-1")
         tepart = TextEnrichedPart(payload)
         bodytmpl = jenv.get_template("body_text_enriched.html")
@@ -140,7 +144,7 @@ def render_body(msg):
             "body": jinja2.Markup(tepart.as_string())
         }
         return bodytmpl.render(context)
-    def render_message_partial(msg):
+    def render_message_partial(msg, extra=None):
         # Default header for get_param is Content-Type
         whole_msg_id = msg.get_param("id")
         if not whole_msg_id in partial_message_cache:
@@ -166,10 +170,10 @@ def render_body(msg):
                         encode_message_id(whole_msg_id),
                         html.escape(whole_msg_id))
 
-    def render_application_octet_stream(msg):
+    def render_application_octet_stream(msg, extra=None):
         return save_part(msg, "attachment")
 
-    def render_multipart_signed(msg):
+    def render_multipart_signed(msg, extra=None):
         content, signature = msg.get_payload()
         with tempfile.NamedTemporaryFile(buffering=0) as content_fh:
             content_fh.write(content.as_bytes())
@@ -193,7 +197,7 @@ def render_body(msg):
         }
         return bodytmpl.render(context)
 
-    def render_application_pgp(msg):
+    def render_application_pgp(msg, extra=None):
         with tempfile.NamedTemporaryFile(buffering=0) as content_fh:
             content_fh.write(msg.get_payload(decode=True))
             r = subprocess.run(["gpg", "--decrypt", content_fh.name],
@@ -216,7 +220,7 @@ def render_body(msg):
         }
         return bodytmpl.render(context)
 
-    def render_multipart_alternative(msg):
+    def render_multipart_alternative(msg, extra=None):
         partshtml = []
         partstypes = []
         for part in msg.get_payload():
@@ -229,24 +233,24 @@ def render_body(msg):
         }
         return bodytmpl.render(context)
 
-    def render_application_x_unknown_content_type_scpfile(msg):
+    def render_application_x_unknown_content_type_scpfile(msg, extra=None):
         bodytmpl = jenv.get_template("body_application_x-unknown-content-type-scpfile.html")
         context = {
             "body": msg.get_payload(decode=True).decode(msg.get_charset() or "iso-8859-1")
         }
         return bodytmpl.render(context)
 
-    def render_application_pgp_signature(msg):
+    def render_application_pgp_signature(msg, extra=None):
         # A PGP signature outside of a multipart/signed - useless
         bodytmpl = jenv.get_template("body_application_pgp-signature.html")
         context = {
         }
         return bodytmpl.render(context)
 
-    def render_application_x_gzip(msg):
+    def render_application_x_gzip(msg, extra=None):
         return save_part(msg, "attachment")
 
-    def render_message_news(msg):
+    def render_message_news(msg, extra=None):
         partshtml = []
         for part in msg.get_payload():
             partshtml.append(render_message(part))
@@ -257,9 +261,36 @@ def render_body(msg):
         }
         return bodytmpl.render(context)
 
-    def render_image_gif(msg):
+    def render_image_gif(msg, extra=None):
         return save_part(msg, "inline")
 
+    def render_multipart_related(msg, extra=None):
+        start = msg.get_param("start")
+        start_part = None
+        # collect content-ids
+        content = {}
+        for i, part in enumerate(msg.get_payload()):
+            content_id = part.get("Content-Id")
+            if start_part is None and (start is None or content_id == start):
+                start_part = part
+                continue
+            if content_id:
+                content[content_id] = {
+                    "i": i,
+                    "part": part,
+                    "url": save_part(part, "_url"),
+                }
+
+
+
+        parthtml = render_body(start_part, content)
+        bodytmpl = jenv.get_template("body_multipart_related.html")
+        context = {
+            "msg": msg,
+            "parts": [parthtml],
+        }
+        return bodytmpl.render(context)
+
     renderers = {
         "text/plain": render_text_plain,
         "multipart/mixed": render_multipart_mixed,
@@ -277,6 +308,7 @@ def render_body(msg):
         "application/x-gzip": render_application_x_gzip,
         "message/news": render_message_news,
         "image/gif": render_image_gif,
+        "multipart/related": render_multipart_related,
     }
     content_type = msg.get_content_type()
     content_disposition = msg.get_content_disposition()
@@ -287,7 +319,7 @@ def render_body(msg):
         # and not try to display.
         bodyhtml = save_part(msg, content_disposition)
     else:
-        bodyhtml = renderers[content_type](msg)
+        bodyhtml = renderers[content_type](msg, extra)
 
     return jinja2.Markup(bodyhtml)
 
@@ -323,11 +355,12 @@ class HTMLPart(html.parser.HTMLParser):
     hide_tags = [ "title" ]
     ignore_tags = [ "html", "head", "body", "marquee", "meta", "form", ]
 
-    def __init__(self):
+    def __init__(self, extra):
         super().__init__()
         self.hide = False
         self.content = []
         self.base = None
+        self.extra = extra or {}
 
     def handle_starttag(self, tag, attrs):
         if tag == "base":
@@ -388,8 +421,7 @@ class HTMLPart(html.parser.HTMLParser):
                 u = urllib.parse.urlparse(url)
                 if u[0] == "cid":
                     print("Encountered src cid attribute", a, file=sys.stderr)
-                    # XXX - implement cid
-                    clean_attrs.append((a[0], url))
+                    clean_attrs.append((a[0], self.extra["<" + u.path + ">"]["url"]))
                 else:
                     print("Ignored src attribute", a, file=sys.stderr)
             elif a[0] == "target":
diff --git a/templates/body_multipart_related.html b/templates/body_multipart_related.html
new file mode 100644
index 0000000..4f0222e
--- /dev/null
+++ b/templates/body_multipart_related.html
@@ -0,0 +1,10 @@
+<div class="partouter">
+    <div class="partheader">
+       multipart/related
+    </div>
+    <div class="partinner">
+        {% for part in parts %}
+            {{part}}
+        {% endfor %}
+    </div>
+</div>