diff --git a/smtp.Dockerfile b/smtp.Dockerfile
index 32efbb5..cd0916c 100644
--- a/smtp.Dockerfile
+++ b/smtp.Dockerfile
@@ -1,4 +1,7 @@
 FROM git.joeac.net/joeac/armv7/msmtp:1.8.32-alpine3.23
 ARG LOCAL_SMTP_PORT
 EXPOSE $LOCAL_SMTP_PORT
+ENV SMTP_PORT=${LOCAL_SMTP_PORT} \
+  SMTP_USER=${LOCAL_SMTP_USER} \
+  SMTP_PASSWORD=${LOCAL_SMTP_PASSWORD}
 COPY smtp/.msmtprc ./