diff --git a/.gitignore b/.gitignore
index c45468f..49018cb 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,3 +1,4 @@
 .envrc
 __pycache__
 venv
+.mypy_cache
diff --git a/deletefb/deletefb.py b/deletefb/deletefb.py
index 4d8c5a9..68a1127 100755
--- a/deletefb/deletefb.py
+++ b/deletefb/deletefb.py
@@ -6,6 +6,7 @@ from .tools.login import login
 from .tools.wall import delete_posts
 from .tools.conversations import traverse_conversations
 from .tools.comments import delete_comments
+from .tools.env_variables import EnvParser
 
 import argparse
 import getpass
@@ -13,8 +14,18 @@ import sys
 
 LOG = logger("deletefb")
 
+
 def run_delete():
     parser = argparse.ArgumentParser()
+    env_parser = EnvParser()
+
+    parser.add_argument(
+        "--help-env",
+        action="store_true",
+        dest="help_env",
+        default=False,
+        help="Print help about environment variables"
+    )
 
     parser.add_argument(
         "-M",
@@ -30,7 +41,7 @@ def run_delete():
     parser.add_argument(
         "-E",
         "--email",
-        required=True,
+        required='--help-env' not in sys.argv,
         dest="email",
         type=str,
         help="Your email address associated with the account"
@@ -48,7 +59,7 @@ def run_delete():
     parser.add_argument(
         "-U",
         "--profile-url",
-        required=True,
+        required='--help-env' not in sys.argv,
         dest="profile_url",
         type=str,
         help="The link to your Facebook profile, e.g. https://www.facebook.com/your.name"
@@ -99,9 +110,23 @@ def run_delete():
         help="Optional path to the Google Chrome (or Chromium) binary"
     )
 
+    env_parser.add_argument(
+        "DELETEFB_RETRY_THRESHOLD",
+        default=5,
+        dest="retry_threshold",
+        type=int,
+        help="Number of refreshes to ensure your wall is empty before quitting"
+    )
+
     args = parser.parse_args()
+    env = env_parser.parse_args()
+
+    if args.help_env:
+        env_parser.print_help()
+        sys.exit(0)
 
     settings["ARCHIVE"] = not args.archive_off
+    settings["RETRY_THRESHOLD"] = env.retry_threshold
 
     if args.year and args.mode not in ("wall", "conversations"):
         parser.error("The --year option is not supported in this mode")
@@ -133,5 +158,6 @@ def run_delete():
         print("Please enter a valid mode")
         sys.exit(1)
 
+
 if __name__ == "__main__":
     run_delete()
diff --git a/deletefb/tools/config.py b/deletefb/tools/config.py
index 078efca..16fd87a 100644
--- a/deletefb/tools/config.py
+++ b/deletefb/tools/config.py
@@ -1,4 +1,5 @@
 settings = {
     "ARCHIVE" : True,
-    "MAX_POSTS" : 5000
+    "MAX_POSTS" : 5000,
+    "RETRY_THRESHOLD": 5
 }
diff --git a/deletefb/tools/env_variables.py b/deletefb/tools/env_variables.py
new file mode 100644
index 0000000..d02ac3e
--- /dev/null
+++ b/deletefb/tools/env_variables.py
@@ -0,0 +1,50 @@
+#!/usr/bin/env python3
+
+import sys
+import os
+import re
+import typing as ty
+
+from types import SimpleNamespace
+
+
+class EnvVar:
+    def __init__(self,
+                 env_key: str,
+                 dest: ty.Optional[str] = None,
+                 type: ty.Type = str,
+                 default: ty.Optional[str] = None,
+                 help: ty.Optional[str] = None):
+
+        assert re.match('^[a-zA-Z_]+[a-zA-Z0-9_]*$', env_key), "Bad env key {0}".format(env_key)
+        self.key = env_key
+        self.dest = dest or env_key.lower()
+        self.type = type
+        self.help = help
+        self.default = default
+
+
+class EnvParser:
+    def __init__(self):
+        self.env_vars = set()
+
+    def add_argument(self, *args, **kwargs):
+        self.env_vars.add(EnvVar(*args, **kwargs))
+
+    def print_help(self):
+        print("environment variables:")
+        for v in self.env_vars:
+            print("  {0}=<{1}>\t{2}".format(v.key, v.type.__name__, v.help or ''))
+
+    def parse_args(self):
+        args = {}
+        for v in self.env_vars:
+            try:
+                args[v.dest] = v.type(os.environ.get(v.key, v.default))
+            except ValueError:
+                print("{0}: error: environment variable {1} should be of type {2}".format(
+                      sys.argv[0].split('/')[-1],
+                      v.key,
+                      v.type.__name__))
+                sys.exit(1)
+        return SimpleNamespace(**args)
diff --git a/deletefb/tools/wall.py b/deletefb/tools/wall.py
index fb8ff69..3ed93d4 100644
--- a/deletefb/tools/wall.py
+++ b/deletefb/tools/wall.py
@@ -26,7 +26,11 @@ def delete_posts(driver,
 
     driver.get(user_profile_url)
 
+    retry_threshold = 0
     for _ in range(MAX_POSTS):
+        if retry_threshold >= settings["RETRY_THRESHOLD"]:
+            break
+
         post_button_sel = "_4xev"
 
         post_content_sel = "userContent"
@@ -36,6 +40,9 @@ def delete_posts(driver,
 
         with archiver("wall") as archive_wall_post:
             while True:
+                if retry_threshold >= settings["RETRY_THRESHOLD"]:
+                    break
+
                 try:
                     timeline_element = driver.find_element_by_class_name(post_button_sel)
 
@@ -67,15 +74,18 @@ def delete_posts(driver,
                             continue
 
                     if not delete_button:
+                        retry_threshold += 1
                         print("Could not find anything to delete")
                         break
+                    else:
+                        retry_threshold = 0
 
                     click_button(driver, delete_button)
                     confirmation_button = driver.find_element_by_class_name("layerConfirm")
 
                     click_button(driver, confirmation_button)
-
                 except SELENIUM_EXCEPTIONS as e:
+                    retry_threshold += 1
                     print(e)
                     continue
                 else: