diff --git a/CHANGELOG.md b/CHANGELOG.md
index 6fdffbab..9e529052 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -8,6 +8,10 @@ System:
 
 * Missing brute force login attack prevention (fail2ban) filters which stopped working on Ubuntu 18.04 were added back.
 
+Mail:
+
+* Incoming messages addressed to more than one local user were rejected because of a bug in spampd packaged by Ubuntu 18.04. A workaround was added.
+
 Contacts/Calendar:
 
 * Upgraded Nextcloud from 13.0.6 to 14.0.6.
diff --git a/setup/mail-postfix.sh b/setup/mail-postfix.sh
index 0c9bc97c..4d66cd58 100755
--- a/setup/mail-postfix.sh
+++ b/setup/mail-postfix.sh
@@ -173,8 +173,11 @@ tools/editconf.py /etc/postfix/main.cf \
 #
 # In a basic setup we would pass mail directly to Dovecot by setting
 # virtual_transport to `lmtp:unix:private/dovecot-lmtp`.
-#
 tools/editconf.py /etc/postfix/main.cf virtual_transport=lmtp:[127.0.0.1]:10025
+# Because of a spampd bug, limit the number of recipients in each connection.
+# See https://github.com/mail-in-a-box/mailinabox/issues/1523.
+tools/editconf.py /etc/postfix/main.cf lmtp_destination_recipient_limit=1
+
 
 # Who can send mail to us? Some basic filters.
 #