diff --git a/test/config/postfix-regexp.cf b/test/config/postfix-regexp.cf
new file mode 100644
index 00000000..ac8e5e73
--- /dev/null
+++ b/test/config/postfix-regexp.cf
@@ -0,0 +1,2 @@
+/^test[0-9][0-9]*@localhost.localdomain/ user1@localhost.localdomain
+/^bounce.*@.*/ external1@otherdomain.tld
diff --git a/test/email-templates/existing-regexp-alias-external.txt b/test/email-templates/existing-regexp-alias-external.txt
new file mode 100644
index 00000000..ab5ecd11
--- /dev/null
+++ b/test/email-templates/existing-regexp-alias-external.txt
@@ -0,0 +1,12 @@
+HELO mail.external.tld
+MAIL FROM: user@external.tld
+RCPT TO: bounce-always@localhost.localdomain
+DATA
+From: Docker Mail Server <dockermailserver@external.tld>
+To: Existing Local User <bounce-always@localhost.localdomain>
+Date: Sat, 22 May 2010 07:43:25 -0400
+Subject: Test Message
+This is a test mail.
+
+.
+QUIT
diff --git a/test/email-templates/existing-regexp-alias-local.txt b/test/email-templates/existing-regexp-alias-local.txt
new file mode 100644
index 00000000..99170500
--- /dev/null
+++ b/test/email-templates/existing-regexp-alias-local.txt
@@ -0,0 +1,12 @@
+HELO mail.external.tld
+MAIL FROM: user@external.tld
+RCPT TO: test123@localhost.localdomain
+DATA
+From: Docker Mail Server <dockermailserver@external.tld>
+To: Existing Local User <test123@localhost.localdomain>
+Date: Sat, 22 May 2010 07:43:25 -0400
+Subject: Test Message
+This is a test mail.
+
+.
+QUIT