diff --git a/emails.py b/emails.py
index 032b532..4a6de1a 100755
--- a/emails.py
+++ b/emails.py
@@ -16,8 +16,6 @@ import smtplib
 import sys
 
 
-
-
 ###############################################################################
 # SETTINGS
 ###############################################################################
@@ -99,7 +97,7 @@ repository_name = email_to[1].rsplit('@', 1)[0]
 request_subscribe   = repository_name.endswith('+subscribe')
 request_unsubscribe = repository_name.endswith('+unsubscribe')
 
-# Remove leading command: from address
+# Remove command from address
 if request_subscribe:   repository_name = repository_name[:-10]
 if request_unsubscribe: repository_name = repository_name[:-12]
 
@@ -127,8 +125,8 @@ except:
 try:
     head_tree = repo.revparse_single('HEAD').tree
 except:
-    logging.error('Could not find HEAD ref: {}'.format(repository_path))
-    exit()
+    logging.warning('Could not find HEAD ref: {}'.format(repository_path))
+    head_tree = None
 
 try:
     subscribers = []
@@ -138,7 +136,7 @@ try:
             subscribers.append(addr)
 except:
     subscribers = []
-    logging.info('Subscribers file not found in {}'.format(repository_path))
+    logging.info('Subscribers file not found or invalid: {}'.format(repository_path))
 
 
 
@@ -147,14 +145,16 @@ except:
 # LISTS SUBSCRIPTION
 ###############################################################################
 
-if request_subscribe \
-and email_from[1] in subscribers:
+if request_subscribe and (email_from[1] in subscribers):
     # Already subscribed
+    
+    logging.info('Already subscribed to {}: {}'.format(repository_path, email_from))
     exit()
 
-if request_unsubscribe \
-and email_from[1] not in subscribers:
-    # No address to removed
+if request_unsubscribe and (email_from[1] not in subscribers):
+    # No address to remove
+    
+    logging.info('Already unsubscribed from {}: {}'.format(repository_path, email_from))
     exit()
 
 if request_subscribe or request_unsubscribe:
@@ -170,19 +170,24 @@ if request_subscribe or request_unsubscribe:
     oid = repo.create_blob('\n'.join(subscribers).encode('UTF-8'))
 
     # Add the blob that we've just created to the HEAD tree
-    head_tree_builder = repo.TreeBuilder(head_tree)
+    head_tree_builder = repo.TreeBuilder(head_tree) if head_tree else repo.TreeBuilder()
     head_tree_builder.insert('subscribers', oid, pygit2.GIT_FILEMODE_BLOB)
     head_tree_oid = head_tree_builder.write()
 
     repo.create_commit(
-        repo.head.name,                     # reference name
+        'HEAD',                             # reference name
         pygit2.Signature('CLIF', '-'),      # author
         pygit2.Signature('CLIF', '-'),      # committer
         commit_message,                     # message
         head_tree_oid,                      # tree of this commit
-        [ repo.head.target ]                # parents commit
+        [] if repo.is_empty else [ repo.head.target ] # parents commit
     )
     
+    if request_subscribe:
+        logging.info('Subscribed to {}: {}'.format(repository_path, email_from))
+    if request_unsubscribe:
+        logging.info('Unsubscribed from {}: {}'.format(repository_path, email_from))
+    
     exit()
 
 
@@ -218,19 +223,24 @@ thread_title = '{} {} {}'.format(
 )
 
 if email_in_reply_to:
-    # The hash of the email that is being replied to
-    parent_message_hash = hashlib.sha256(email_in_reply_to.encode('utf-8')).hexdigest()[:8]
-
-    # Find the thread (tree) containing the parent message
-    for obj in head_tree:
-        if obj.type_str == 'tree' and parent_message_hash + '.email' in obj:
-            thread_tree = obj
-            thread_title = obj.name
-            break
-    
-    # We only accept emails in reply to existing messages
-    if not thread_tree:
-        logging.debug('In-Reply-To ID not found in repository: {}'.format(email_in_reply_to))
+    try:
+        assert head_tree
+        
+        # The hash of the email that is being replied to
+        parent_message_hash = hashlib.sha256(email_in_reply_to.encode('utf-8')).hexdigest()[:8]
+
+        # Find the thread (tree) containing the parent message
+        for obj in head_tree:
+            if obj.type_str == 'tree' and parent_message_hash + '.email' in obj:
+                thread_tree = obj
+                thread_title = obj.name
+                break
+        
+        assert thread_tree
+        
+    except:
+        # We only accept emails as reply to existing messages
+        logging.debug('In-Reply-To message ID not found in repository: {}'.format(email_in_reply_to))
         exit()
 
 # Add the new email BLOB to the git store
@@ -242,17 +252,17 @@ thread_tree_builder.insert(email_id_hash + '.email', message_oid, pygit2.GIT_FIL
 thread_tree_oid = thread_tree_builder.write()
 
 # Add the thread tree to the HEAD tree
-head_tree_builder = repo.TreeBuilder(head_tree)
+head_tree_builder = repo.TreeBuilder(head_tree) if head_tree else repo.TreeBuilder()
 head_tree_builder.insert(thread_title, thread_tree_oid, pygit2.GIT_FILEMODE_TREE)
 head_tree_oid = head_tree_builder.write()
 
 repo.create_commit(
-    repo.head.name,                     # reference name
+    'HEAD',                             # reference name
     pygit2.Signature('CLIF', '-'),      # author
     pygit2.Signature('CLIF', '-'),      # committer
     'New email.',                       # message
     head_tree_oid,                      # tree of this commit
-    [ repo.head.target ]                # parents commit
+    [] if repo.is_empty else [ repo.head.target ] # parents commit
 )