Not much was changed in that new update, core features still work, but some code could be rewritten

Author: Taaku18

cogs/modmail.py

@@ -18,7 +18,7 @@
 from core.utils import format_preview, User
 
 
-class Modmail:
+class Modmail(commands.Cog):
     """Commands directly related to Modmail functionality."""
 
     def __init__(self, bot: Bot):

cogs/plugins.py

@@ -19,7 +19,7 @@ class DownloadError(Exception):
     pass
 
 
-class Plugins:
+class Plugins(commands.Cog):
     """Plugins expand Modmail functionality by allowing third-party addons.
 
     These addons could have a range of features from moderation to simply

cogs/utility.py

@@ -26,7 +26,7 @@
 logger = logging.getLogger('Modmail')
 
 
-class Utility:
+class Utility(commands.Cog):
     """General commands that provide utility"""
 
     def __init__(self, bot: Bot):
@@ -52,7 +52,7 @@ async def format_cog_help(self, ctx, cog):
         fmts = ['']
         for cmd in sorted(self.bot.commands,
                           key=lambda cmd: cmd.qualified_name):
-            if cmd.instance is cog and not cmd.hidden and \
+            if cmd.cog is cog and not cmd.hidden and \
                     await self.verify_checks(ctx, cmd):
                 new_fmt = f'`{prefix + cmd.qualified_name}` - '
                 new_fmt += f'{cmd.short_doc}\n'
@@ -580,6 +580,7 @@ async def set_presence(self, *,
             presence['status'] = (status, msg)
         return presence
 
+    @commands.Cog.listener()
     async def on_ready(self):
         # Wait until config cache is populated with stuff from db
         await self.bot.config.wait_until_ready()

requirements.txt

@@ -1,4 +1,4 @@
-git+https://github.com/Rapptz/discord.py@7f4c57dd5ad20b7fa10aea485f674a4bc24b9547
+git+https://github.com/Rapptz/discord.py
 colorama>=0.4.0
 python-dateutil>=2.7.0
 emoji>=0.2