diff --git a/app/email_utils.py b/app/email_utils.py
index 836e42c3..b631ce59 100644
--- a/app/email_utils.py
+++ b/app/email_utils.py
@@ -1474,7 +1474,7 @@ def get_spamd_result(msg: Message) -> Optional[SpamdResult]:
 
 
 def generate_verp_email(
-    verp_type: VerpType, object_id: int, sender_domain: Optional[str]
+    verp_type: VerpType, object_id: int, sender_domain: Optional[str] = None
 ) -> str:
     # Encoded as a list to minimize size of email address
     data = [verp_type.bounce_forward.value, object_id, int(time.time())]
diff --git a/email_handler.py b/email_handler.py
index 5ba882b7..3a4fa3a5 100644
--- a/email_handler.py
+++ b/email_handler.py
@@ -157,7 +157,8 @@ from app.models import (
     DomainDeletedAlias,
     Notification,
     DmarcCheckResult,
-    SPFCheckResult, VerpType,
+    SPFCheckResult,
+    VerpType,
 )
 from app.pgp_utils import PGPException, sign_data_with_pgpy, sign_data
 from app.utils import sanitize_email
diff --git a/tests/test_email_handler.py b/tests/test_email_handler.py
index 1f7cdd59..4f266ff4 100644
--- a/tests/test_email_handler.py
+++ b/tests/test_email_handler.py
@@ -3,15 +3,15 @@ from email.message import EmailMessage
 from aiosmtpd.smtp import Envelope
 
 import email_handler
-from app.config import BOUNCE_EMAIL
 from app.email import headers, status
+from app.email_utils import generate_verp_email
 from app.models import (
     User,
     Alias,
     AuthorizedAddress,
     IgnoredEmail,
     EmailLog,
-    Notification,
+    Notification, VerpType,
 )
 from email_handler import (
     get_mailbox_from_mail_from,
@@ -127,7 +127,7 @@ def test_prevent_5xx_from_spf(flask_client):
         {"alias_email": alias.email, "spf_result": "R_SPF_FAIL"},
     )
     envelope = Envelope()
-    envelope.mail_from = BOUNCE_EMAIL.format(999999999999999999)
+    envelope.mail_from = generate_verp_email(VerpType.bounce_forward, 99999999999999)
     envelope.rcpt_tos = [msg["to"]]
     result = email_handler.MailHandler()._handle(envelope, msg)
     assert result == status.E216
@@ -141,7 +141,7 @@ def test_preserve_5xx_with_valid_spf(flask_client):
         {"alias_email": alias.email, "spf_result": "R_SPF_ALLOW"},
     )
     envelope = Envelope()
-    envelope.mail_from = BOUNCE_EMAIL.format(999999999999999999)
+    envelope.mail_from = generate_verp_email(VerpType.bounce_forward, 99999999999999)
     envelope.rcpt_tos = [msg["to"]]
     result = email_handler.MailHandler()._handle(envelope, msg)
     assert result == status.E512
@@ -155,7 +155,7 @@ def test_preserve_5xx_with_no_header(flask_client):
         {"alias_email": alias.email},
     )
     envelope = Envelope()
-    envelope.mail_from = BOUNCE_EMAIL.format(999999999999999999)
+    envelope.mail_from = generate_verp_email(VerpType.bounce_forward, 99999999999999)
     envelope.rcpt_tos = [msg["to"]]
     result = email_handler.MailHandler()._handle(envelope, msg)
     assert result == status.E512