diff --git a/CHANGELOG.md b/CHANGELOG.md
index 949281b..b0e6f59 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -5,6 +5,7 @@ In Development
 --------------
 
 * Roundcube updated to version 1.1.4.
+* When there's a problem deliverying an outgoing message, a new 'warning' bounce will come after 3 hours and the box will stop trying after 2 days (instead of 5).
 * On multi-homed machines, Postfix now binds to the right network interface when sending outbound mail so that SPF checks on the receiving end will pass.
 * TLS certificate provisioning would crash if DNS propagation was in progress and a challenge failed.
 * Backup times were displayed with the wrong time zone.
diff --git a/setup/mail-postfix.sh b/setup/mail-postfix.sh
index bf211ca..a3b87a9 100755
--- a/setup/mail-postfix.sh
+++ b/setup/mail-postfix.sh
@@ -69,6 +69,14 @@ tools/editconf.py /etc/postfix/main.cf \
 	smtpd_banner="\$myhostname ESMTP Hi, I'm a Mail-in-a-Box (Ubuntu/Postfix; see https://mailinabox.email/)" \
 	mydestination=localhost
 
+# Tweak some queue settings:
+# * Inform users when their e-mail delivery is delayed more than 3 hours (default is not to warn).
+# * Stop trying to send an undeliverable e-mail after 2 days (instead of 5), and for bounce messages just try for 1 day.
+tools/editconf.py /etc/postfix/main.cf \
+	delay_warning_time=3h \
+	maximal_queue_lifetime=2d \
+	bounce_queue_lifetime=1d
+
 # ### Outgoing Mail
 
 # Enable the 'submission' port 587 smtpd server and tweak its settings.