diff --git a/parsedmarc/utils.py b/parsedmarc/utils.py
index 24f6dd2..7b8d211 100644
--- a/parsedmarc/utils.py
+++ b/parsedmarc/utils.py
@@ -1,11 +1,18 @@
+# -*- coding: utf-8 -*-
+
 """Utility functions that might be useful for other projects"""
 
+from __future__ import annotations
+
+from typing import Optional, Union
+
 import logging
 import os
 from datetime import datetime
 from datetime import timezone
 from datetime import timedelta
 from collections import OrderedDict
+from expiringdict import ExpiringDict
 import tempfile
 import subprocess
 import shutil
@@ -60,12 +67,12 @@ class DownloadError(RuntimeError):
     """Raised when an error occurs when downloading a file"""
 
 
-def decode_base64(data):
+def decode_base64(data: str) -> bytes:
     """
     Decodes a base64 string, with padding being optional
 
     Args:
-        data: A base64 encoded string
+        data (str): A base64 encoded string
 
     Returns:
         bytes: The decoded bytes
@@ -78,7 +85,7 @@ def decode_base64(data):
     return base64.b64decode(data)
 
 
-def get_base_domain(domain):
+def get_base_domain(domain: str) -> str:
     """
     Gets the base domain name for the given domain
 
@@ -102,7 +109,12 @@ def get_base_domain(domain):
     return publicsuffix
 
 
-def query_dns(domain, record_type, cache=None, nameservers=None, timeout=2.0):
+def query_dns(domain: str,
+              record_type: str,
+              *,
+              cache: Optional[ExpiringDict] = None,
+              nameservers: list[str] = None,
+              timeout:int = 2.0) -> list[str]:
     """
     Queries DNS
 
@@ -163,7 +175,11 @@ def query_dns(domain, record_type, cache=None, nameservers=None, timeout=2.0):
     return records
 
 
-def get_reverse_dns(ip_address, cache=None, nameservers=None, timeout=2.0):
+def get_reverse_dns(ip_address, 
+                    *,
+                    cache: Optional[ExpiringDict] = None,
+                    nameservers: list[str] = None,
+                    timeout:int = 2.0) -> str:
     """
     Resolves an IP address to a hostname using a reverse DNS query
 
@@ -191,7 +207,7 @@ def get_reverse_dns(ip_address, cache=None, nameservers=None, timeout=2.0):
     return hostname
 
 
-def timestamp_to_datetime(timestamp):
+def timestamp_to_datetime(timestamp: int) ->  datetime:
     """
     Converts a UNIX/DMARC timestamp to a Python ``datetime`` object
 
@@ -204,7 +220,7 @@ def timestamp_to_datetime(timestamp):
     return datetime.fromtimestamp(int(timestamp))
 
 
-def timestamp_to_human(timestamp):
+def timestamp_to_human(timestamp: int) -> str:
     """
     Converts a UNIX/DMARC timestamp to a human-readable string
 
@@ -217,7 +233,9 @@ def timestamp_to_human(timestamp):
     return timestamp_to_datetime(timestamp).strftime("%Y-%m-%d %H:%M:%S")
 
 
-def human_timestamp_to_datetime(human_timestamp, to_utc=False):
+def human_timestamp_to_datetime(human_timestamp: str,
+                                *,
+                                to_utc: Optional[bool] = False) -> datetime:
     """
     Converts a human-readable timestamp into a Python ``datetime`` object
 
@@ -236,7 +254,7 @@ def human_timestamp_to_datetime(human_timestamp, to_utc=False):
     return dt.astimezone(timezone.utc) if to_utc else dt
 
 
-def human_timestamp_to_unix_timestamp(human_timestamp):
+def human_timestamp_to_unix_timestamp(human_timestamp: str) -> int:
     """
     Converts a human-readable timestamp into a UNIX timestamp
 
@@ -250,7 +268,9 @@ def human_timestamp_to_unix_timestamp(human_timestamp):
     return human_timestamp_to_datetime(human_timestamp).timestamp()
 
 
-def get_ip_address_country(ip_address, db_path=None):
+def get_ip_address_country(ip_address:str,
+                           *,
+                           db_path: Optional[str ] = None) -> str:
     """
     Returns the ISO code for the country associated
     with the given IPv4 or IPv6 address
@@ -314,12 +334,13 @@ def get_ip_address_country(ip_address, db_path=None):
 
 def get_service_from_reverse_dns_base_domain(
     base_domain,
-    always_use_local_file=False,
-    local_file_path=None,
-    url=None,
-    offline=False,
-    reverse_dns_map=None,
-):
+    *,
+    always_use_local_file: Optional[bool] = False,
+    local_file_path: Optional[bool] = None,
+    url: Optional[bool] = None,
+    offline: Optional[bool ] = False,
+    reverse_dns_map: Optional[bool] = None,
+) -> str:
     """
     Returns the service name of a given base domain name from reverse DNS.
 
@@ -389,16 +410,17 @@ def get_service_from_reverse_dns_base_domain(
 
 def get_ip_address_info(
     ip_address,
-    ip_db_path=None,
-    reverse_dns_map_path=None,
-    always_use_local_files=False,
-    reverse_dns_map_url=None,
-    cache=None,
-    reverse_dns_map=None,
-    offline=False,
-    nameservers=None,
-    timeout=2.0,
-):
+    *,
+    ip_db_path:Optional[str]=None,
+    reverse_dns_map_path:Optional[str]=None,
+    always_use_local_files:Optional[bool]=False,
+    reverse_dns_map_url: Optional[bool ] = None,
+    cache: Optional[ExpiringDict]=None,
+    reverse_dns_map: Optional[bool] = None,
+    offline: Optional[bool]=False,
+    nameservers:Optional[list[str]]=None,
+    timeout:Optional[float]=2.0,
+) -> OrderedDict[str, str]:
     """
     Returns reverse DNS and country information for the given IP address
 
@@ -416,7 +438,7 @@ def get_ip_address_info(
         timeout (float): Sets the DNS timeout in seconds
 
     Returns:
-        OrderedDict: ``ip_address``, ``reverse_dns``
+        OrderedDict: ``ip_address``, ``reverse_dns``, ``country``
 
     """
     ip_address = ip_address.lower()
@@ -463,7 +485,7 @@ def get_ip_address_info(
     return info
 
 
-def parse_email_address(original_address):
+def parse_email_address(original_address: str) -> OrderedDict[str,str]:
     if original_address[0] == "":
         display_name = None
     else:
@@ -486,7 +508,7 @@ def parse_email_address(original_address):
     )
 
 
-def get_filename_safe_string(string):
+def get_filename_safe_string(string: str) -> str:
     """
     Converts a string to a string that is safe for a filename
 
@@ -508,7 +530,7 @@ def get_filename_safe_string(string):
     return string
 
 
-def is_mbox(path):
+def is_mbox(path: str) -> bool:
     """
     Checks if the given content is an MBOX mailbox file
 
@@ -529,7 +551,7 @@ def is_mbox(path):
     return _is_mbox
 
 
-def is_outlook_msg(content):
+def is_outlook_msg(content) -> bool:
     """
     Checks if the given content is an Outlook msg OLE/MSG file
 
@@ -544,7 +566,7 @@ def is_outlook_msg(content):
     )
 
 
-def convert_outlook_msg(msg_bytes):
+def convert_outlook_msg(msg_bytes: bytes) -> str:
     """
     Uses the ``msgconvert`` Perl utility to convert an Outlook MS file to
     standard RFC 822 format
@@ -580,7 +602,9 @@ def convert_outlook_msg(msg_bytes):
     return rfc822
 
 
-def parse_email(data, strip_attachment_payloads=False):
+def parse_email(data: Union[bytes, str],
+                *,
+                strip_attachment_payloads: Optional[bool]=False):
     """
     A simplified email parser