diff --git a/scripts/generate-dns-zone.sh b/scripts/generate-dns-zone.sh
index f7f08ec2..4243f6d4 100755
--- a/scripts/generate-dns-zone.sh
+++ b/scripts/generate-dns-zone.sh
@@ -1,5 +1,6 @@
 #!/bin/sh
 : ${CHATMAIL_DOMAIN:=c1.testrun.org}
+: ${CHATMAIL_SERVER:=$CHATMAIL_DOMAIN}
 : ${CHATMAIL_SSH:=$CHATMAIL_DOMAIN}
 
 set -e
@@ -8,16 +9,22 @@ EMAIL="root@$CHATMAIL_DOMAIN"
 ACME_ACCOUNT_URL="$($SSH -- acmetool account-url)"
 
 cat <<EOF
-$CHATMAIL_DOMAIN. MX 10 $CHATMAIL_DOMAIN.
-$CHATMAIL_DOMAIN. TXT "v=spf1 a:$CHATMAIL_DOMAIN -all"
+$CHATMAIL_DOMAIN. MX 10 $CHATMAIL_SERVER.
+$CHATMAIL_DOMAIN. TXT "v=spf1 a:$CHATMAIL_SERVER -all"
 _dmarc.$CHATMAIL_DOMAIN. TXT "v=DMARC1;p=reject;rua=mailto:$EMAIL;ruf=mailto:$EMAIL;fo=1;adkim=r;aspf=r"
-_submission._tcp.$CHATMAIL_DOMAIN.  SRV 0 1 587 $CHATMAIL_SERVER.
-_submissions._tcp.$CHATMAIL_DOMAIN. SRV 0 1 465 $CHATMAIL_SERVER.
-_imap._tcp.$CHATMAIL_DOMAIN.        SRV 0 1 143 $CHATMAIL_SERVER.
-_imaps._tcp.$CHATMAIL_DOMAIN.       SRV 0 1 993 $CHATMAIL_SERVER.
+_submission._tcp.$CHATMAIL_SERVER.  SRV 0 1 587 $CHATMAIL_SERVER.
+_submissions._tcp.$CHATMAIL_SERVER. SRV 0 1 465 $CHATMAIL_SERVER.
+_imap._tcp.$CHATMAIL_SERVER.        SRV 0 1 143 $CHATMAIL_SERVER.
+_imaps._tcp.$CHATMAIL_SERVER.       SRV 0 1 993 $CHATMAIL_SERVER.
 $CHATMAIL_DOMAIN. IN CAA 128 issue "letsencrypt.org;accounturi=$ACME_ACCOUNT_URL"
 _mta-sts.$CHATMAIL_DOMAIN. IN TXT "v=STSv1; id=$(date -u '+%Y%m%d%H%M')"
-mta-sts.$CHATMAIL_DOMAIN. IN CNAME $CHATMAIL_SERVER.
-_smtp._tls.$CHATMAIL_DOMAIN. IN TXT "v=TLSRPTv1;rua=mailto:$EMAIL"
+mta-sts.$CHATMAIL_SERVER. IN CNAME $CHATMAIL_SERVER.
+_smtp._tls.$CHATMAIL_SERVER. IN TXT "v=TLSRPTv1;rua=mailto:$EMAIL"
 EOF
+if [ "$CHATMAIL_DOMAIN" != "$CHATMAIL_SERVER" ]; then
+cat <<EOF
+mta-sts.$CHATMAIL_DOMAIN. IN CNAME mta-sts.$CHATMAIL_SERVER.
+_smtp._tls.$CHATMAIL_DOMAIN. IN CNAME _smtp._tls.$CHATMAIL_SERVER.
+EOF
+fi
 $SSH opendkim-genzone -F | sed 's/^;.*$//;/^$/d'