remove unique constraint on TransactionalEmail.email

app/email_utils.py

@@ -298,9 +298,7 @@ def send_email(
 
     msg_raw = to_bytes(msg)
 
-    transaction = TransactionalEmail.get_by(email=to_email)
-    if not transaction:
-        transaction = TransactionalEmail.create(email=to_email, commit=True)
+    transaction = TransactionalEmail.create(email=to_email, commit=True)
 
     # use a different envelope sender for each transactional email (aka VERP)
     smtp.sendmail(TRANSACTIONAL_BOUNCE_EMAIL.format(transaction.id), to_email, msg_raw)

app/models.py

@@ -2421,7 +2421,7 @@ class TransactionalEmail(db.Model, ModelMixin):
     Deleted after 7 days
     """
 
-    email = db.Column(db.String(256), nullable=False, unique=True)
+    email = db.Column(db.String(256), nullable=False, unique=False)
 
 
 class Payout(db.Model, ModelMixin):

migrations/versions/2021_092111_bc75acacc98e_.py

@@ -0,0 +1,29 @@
+"""empty message
+
+Revision ID: bc75acacc98e
+Revises: 7a105bfc0cd0
+Create Date: 2021-09-21 11:15:15.573629
+
+"""
+import sqlalchemy_utils
+from alembic import op
+import sqlalchemy as sa
+
+
+# revision identifiers, used by Alembic.
+revision = 'bc75acacc98e'
+down_revision = '7a105bfc0cd0'
+branch_labels = None
+depends_on = None
+
+
+def upgrade():
+    # ### commands auto generated by Alembic - please adjust! ###
+    op.drop_constraint('transactional_email_email_key', 'transactional_email', type_='unique')
+    # ### end Alembic commands ###
+
+
+def downgrade():
+    # ### commands auto generated by Alembic - please adjust! ###
+    op.create_unique_constraint('transactional_email_email_key', 'transactional_email', ['email'])
+    # ### end Alembic commands ###