diff --git a/entrypoint.sh b/entrypoint.sh
index 900730f..0358815 100755
--- a/entrypoint.sh
+++ b/entrypoint.sh
@@ -1,5 +1,6 @@
 #!/bin/sh
 
 [ -n "${MAILER_HOST}" ] && sed -r "/^mailhub=/s/.*/mailhub=${MAILER_HOST}/" /etc/ssmtp/ssmtp.conf > ~/ssmtp.conf && cat ~/ssmtp.conf > /etc/ssmtp/ssmtp.conf
+[ -n "${MAILER_REWRITEDOMAIN}" ] && sed -r "/^#?rewriteDomain=/s/.*/rewriteDomain=${MAILER_REWRITEDOMAIN}/" /etc/ssmtp/ssmtp.conf > ~/ssmtp.conf && cat ~/ssmtp.conf > /etc/ssmtp/ssmtp.conf
 
 exec $@