diff --git a/app/auth/views/register.py b/app/auth/views/register.py
index a616771c..0fa89276 100644
--- a/app/auth/views/register.py
+++ b/app/auth/views/register.py
@@ -46,7 +46,7 @@ def register():
             if personal_email_already_used(email):
                 flash(f"Email {email} already used", "error")
             else:
-                LOG.debug("create user %s", form.email.data)
+                LOG.debug("create user %s", email)
                 user = User.create(
                     email=email,
                     name="",
diff --git a/app/auth/views/resend_activation.py b/app/auth/views/resend_activation.py
index 88292f5b..ea8d10c6 100644
--- a/app/auth/views/resend_activation.py
+++ b/app/auth/views/resend_activation.py
@@ -17,7 +17,7 @@ def resend_activation():
     form = ResendActivationForm(request.form)
 
     if form.validate_on_submit():
-        user = User.filter_by(email=form.email.data).first()
+        user = User.filter_by(email=form.email.data.strip().lower()).first()
 
         if not user:
             flash("There is no such email", "warning")
diff --git a/app/dashboard/views/alias_contact_manager.py b/app/dashboard/views/alias_contact_manager.py
index 3e65fd18..cf899136 100644
--- a/app/dashboard/views/alias_contact_manager.py
+++ b/app/dashboard/views/alias_contact_manager.py
@@ -72,7 +72,7 @@ def alias_contact_manager(alias_id):
     if request.method == "POST":
         if request.form.get("form-name") == "create":
             if new_contact_form.validate():
-                contact_addr = new_contact_form.email.data.strip()
+                contact_addr = new_contact_form.email.data.strip().lower()
 
                 # generate a reply_email, make sure it is unique
                 # not use while to avoid infinite loop
diff --git a/app/dashboard/views/setting.py b/app/dashboard/views/setting.py
index 97e94ed3..8b3b6442 100644
--- a/app/dashboard/views/setting.py
+++ b/app/dashboard/views/setting.py
@@ -67,10 +67,10 @@ def setting():
         if request.form.get("form-name") == "update-email":
             if change_email_form.validate():
                 if (
-                    change_email_form.email.data != current_user.email
+                    change_email_form.email.data.lower().strip() != current_user.email
                     and not pending_email
                 ):
-                    new_email = change_email_form.email.data
+                    new_email = change_email_form.email.data.strip().lower()
 
                     # check if this email is not already used
                     if personal_email_already_used(new_email) or Alias.get_by(