Confirmation emails aren't being sent to users and there's nothing in the logs that make it obvious what's happening.

ERROR 2026-02-12 14:15:11,250 1985547 django.request Internal Server Error: /archives/list/soas@lists.sugarlabs.org/thread/CVAUPR7L6AYTNZXIWHQ263A6ZJUROTRC/ 233825 Traceback (most recent call last): 233826 File "/opt/mailman/venv/lib/python3.10/site-packages/django/core/handlers/exception.py", line 55, in inner 233827 response = get_response(request) 233828 File "/opt/mailman/venv/lib/python3.10/site-packages/django/core/handlers/base.py", line 197, in _get_response 233829 response = wrapped_callback(request, *callback_args, **callback_kwargs) 233830 File "/opt/mailman/venv/lib/python3.10/site-packages/hyperkitty/lib/view_helpers.py", line 137, in inner 233831 return func(request, *args, **kwargs) 233832 File "/opt/mailman/venv/lib/python3.10/site-packages/hyperkitty/views/thread.py", line 238, in thread_index 233833 return render(request, "hyperkitty/thread.html", context=context) 233834 File "/opt/mailman/venv/lib/python3.10/site-packages/django/shortcuts.py", line 25, in render 233835 content = loader.render_to_string(template_name, context, request, using=using) 233836 File "/opt/mailman/venv/lib/python3.10/site-packages/django/template/loader.py", line 62, in render_to_string 233837 return template.render(context, request) 233838 File "/opt/mailman/venv/lib/python3.10/site-packages/django/template/backends/django.py", line 107, in render 233839 return self.template.render(context) 233840 File "/opt/mailman/venv/lib/python3.10/site-packages/django/template/base.py", line 172, in render 233841 return self._render(context) 233842 File "/opt/mailman/venv/lib/python3.10/site-packages/django/template/base.py", line 164, in _render 233843 return self.nodelist.render(context) 233844 File "/opt/mailman/venv/lib/python3.10/site-packages/django/template/base.py", line 1018, in render 233845 return SafeString("".join([node.render_annotated(context) for node in self])) 233846 File "/opt/mailman/venv/lib/python3.10/site-packages/django/template/base.py", line 1018, in <listcomp> 233847 return SafeString("".join([node.render_annotated(context) for node in self])) 233848 File "/opt/mailman/venv/lib/python3.10/site-packages/django/template/base.py", line 979, in render_annotated 233849 return self.render(context) 233850 File "/opt/mailman/venv/lib/python3.10/site-packages/django/template/loader_tags.py", line 159, in render 233851 return compiled_parent._render(context) 233852 File "/opt/mailman/venv/lib/python3.10/site-packages/django/template/base.py", line 164, in _render 233853 return self.nodelist.render(context) 233854 File "/opt/mailman/venv/lib/python3.10/site-packages/django/template/base.py", line 1018, in render 233855 return SafeString("".join([node.render_annotated(context) for node in self])) 233856 File "/opt/mailman/venv/lib/python3.10/site-packages/django/template/base.py", line 1018, in <listcomp> 233857 return SafeString("".join([node.render_annotated(context) for node in self])) 233858 File "/opt/mailman/venv/lib/python3.10/site-packages/django/template/base.py", line 979, in render_annotated 233859 return self.render(context) 233860 File "/opt/mailman/venv/lib/python3.10/site-packages/django/template/loader_tags.py", line 65, in render 233861 result = block.nodelist.render(context) 233862 File "/opt/mailman/venv/lib/python3.10/site-packages/django/template/base.py", line 1018, in render 233863 return SafeString("".join([node.render_annotated(context) for node in self])) 233864 File "/opt/mailman/venv/lib/python3.10/site-packages/django/template/base.py", line 1018, in <listcomp> 233865 return SafeString("".join([node.render_annotated(context) for node in self])) 233866 File "/opt/mailman/venv/lib/python3.10/site-packages/django/template/base.py", line 979, in render_annotated 233867 return self.render(context) 233868 File "/opt/mailman/venv/lib/python3.10/site-packages/django/template/loader_tags.py", line 210, in render 233869 return template.render(context) 233870 File "/opt/mailman/venv/lib/python3.10/site-packages/django/template/base.py", line 174, in render 233871 return self._render(context) 233872 File "/opt/mailman/venv/lib/python3.10/site-packages/django/template/base.py", line 164, in _render 233873 return self.nodelist.render(context) 233874 File "/opt/mailman/venv/lib/python3.10/site-packages/django/template/base.py", line 1018, in render 233875 return SafeString("".join([node.render_annotated(context) for node in self])) 233876 File "/opt/mailman/venv/lib/python3.10/site-packages/django/template/base.py", line 1018, in <listcomp> 233877 return SafeString("".join([node.render_annotated(context) for node in self])) 233878 File "/opt/mailman/venv/lib/python3.10/site-packages/django/template/base.py", line 979, in render_annotated 233879 return self.render(context) 233880 File "/opt/mailman/venv/lib/python3.10/site-packages/django/template/base.py", line 1077, in render 233881 output = self.filter_expression.resolve(context) 233882 File "/opt/mailman/venv/lib/python3.10/site-packages/django/template/base.py", line 750, in resolve 233883 new_obj = func(obj, *arg_vals) 233884 File "/opt/mailman/venv/lib/python3.10/site-packages/hyperkitty/templatetags/decorate.py", line 42, in render 233885 return mark_safe(text_renderer(content)) 233886 File "/opt/mailman/venv/lib/python3.10/site-packages/mistune/markdown.py", line 120, in __call__ 233887 return self.parse(s)[0] 233888 File "/opt/mailman/venv/lib/python3.10/site-packages/mistune/markdown.py", line 93, in parse 233889 self.block.parse(state) 233890 File "/opt/mailman/venv/lib/python3.10/site-packages/mistune/block_parser.py", line 458, in parse 233891 end_pos2 = self.parse_method(m, state) 233892 File "/opt/mailman/venv/lib/python3.10/site-packages/mistune/core.py", line 216, in parse_method 233893 return func(m, state) 233894 File "/opt/mailman/venv/lib/python3.10/site-packages/mistune/block_parser.py", line 369, in parse_block_quote 233895 text, end_pos = self.extract_block_quote(m, state) 233896 File "/opt/mailman/venv/lib/python3.10/site-packages/mistune/block_parser.py", line 346, in extract_block_quote 233897 end_pos = self.parse_method(m4, state) 233898 File "/opt/mailman/venv/lib/python3.10/site-packages/mistune/core.py", line 216, in parse_method 233899 return func(m, state) 233900 File "/opt/mailman/venv/lib/python3.10/site-packages/mistune/block_parser.py", line 388, in parse_list 233901 return parse_list(self, m, state) 233902 File "/opt/mailman/venv/lib/python3.10/site-packages/mistune/list_parser.py", line 64, in parse_list 233903 groups = _parse_list_item(block, bullet, groups, token, state, rules) 233904 File "/opt/mailman/venv/lib/python3.10/site-packages/mistune/list_parser.py", line 178, in _parse_list_item 233905 block.parse(child, rules) 233906 File "/opt/mailman/venv/lib/python3.10/site-packages/mistune/block_parser.py", line 458, in parse 233907 end_pos2 = self.parse_method(m, state) 233908 File "/opt/mailman/venv/lib/python3.10/site-packages/mistune/core.py", line 214, in parse_method 233909 assert lastgroup 233910 AssertionError

This is the last error in mailmanweb.log, the errors before that are similar.