diff --git a/.gitignore b/.gitignore
index 74cfe46f18347a06c763a257a342671c52693c0c..3d5134a515c12aa4cc1bdf1f4ef38c6d09013202 100644
--- a/.gitignore
+++ b/.gitignore
@@ -3,6 +3,7 @@
 *.csv
 *.xlsx
 *.html
+*.zip
 
 # Byte-compiled / optimized / DLL files
 __pycache__/
diff --git a/send_mail.py b/send_mail.py
index bcbcb5aa553277bec41da98df5657de6a3d7cb0f..67ea3b00f0bc92e516f2d61f99241a20ac204c9e 100644
--- a/send_mail.py
+++ b/send_mail.py
@@ -213,6 +213,9 @@ def main() -> None:
                 email = row[Constants.PolyOpinion.email]
                 token = row[Constants.PolyOpinion.token]
 
+                if not first_name or not email or not token:
+                    raise ValueError(f"Missing data for {email}")
+
                 vote_url = args.base_url.update_query(token=token)
                 html_content = template.render(first_name=first_name, vote_url=vote_url)