diff --git a/files/new_mail_alias b/files/new_mail_alias
index 7a4bac1..b8d91d8 100644
--- a/files/new_mail_alias
+++ b/files/new_mail_alias
@@ -1,5 +1,5 @@
 #!/bin/bash
-set -uo pipefail
+
 # shellcheck disable=SC1091
 [ -r /var/lib/from_repos/ad_scripts/shared_functions.sh ] && . /var/lib/from_repos/ad_scripts/shared_functions.sh
 function usage() {
@@ -98,7 +98,7 @@ fi
 
 while [ "${alias}" == "" ]
 do
-    random_string=$(LC_ALL=C tr -dc A-Za-z0-9 </dev/urandom | head -c "${alias_length}")
+    random_string=$(LC_ALL=C tr -dc a-z0-9 </dev/urandom | head -c "${alias_length}")
     existing=$(echo "SELECT source FROM mail.forwardings where source = '${random_string}@${domain}';" |mysql mail |grep -v '^source$')
     if [ -z "${existing}" ]; then
         alias="${random_string}@${domain}"