diff --git a/README.md b/README.md
--- a/README.md
+++ b/README.md
@@ -109,6 +109,14 @@
 PHABRICATOR_DOMAIN            | mailgun.domain                  | The domain of the Phabricator instance
 PHABRICATOR_MAILGUN_APIKEY    | mailgun.api-key                 | Your Mailgun API key
 
+Environment you should pass if you use the legacy SendGrid mail adapter:
+
+Variable                      | Phabricator config variable     | Description
+------------------------------|---------------------------------|------------
+PHABRICATOR_USE_SENDGRID      | metamta.mail-adapter            | If set, use SendGrid as mail adapter
+PHABRICATOR_SENDGRID_APIUSER  | sendgrid.api-user               | Your SendGrid API username
+PHABRICATOR_SENDGRID_APIKEY   | sendgrid.api-key                | Your SendGrid API key
+
 Environment from linked containers:
 
 Variable                      | Phabricator config variable     | Description
diff --git a/files/usr/local/bin/setup-phabricator b/files/usr/local/bin/setup-phabricator
--- a/files/usr/local/bin/setup-phabricator
+++ b/files/usr/local/bin/setup-phabricator
@@ -25,6 +25,15 @@
 		bin/config set mailgun.api-key $PHABRICATOR_MAILGUN_APIKEY
 	fi
 fi
+if [ -n "$PHABRICATOR_USE_SENDGRID" ]; then
+	bin/config set metamta.mail-adapter PhabricatorMailImplementationSendGridAdapter
+	if [ -n "$PHABRICATOR_SENDGRID_APIUSER" ]; then
+		bin/config set sendgrid.api-user $PHABRICATOR_SENDGRID_APIUSER
+	fi
+	if [ -n "$PHABRICATOR_SENDGRID_APIKEY" ]; then
+		bin/config set sendgrid.api-key $PHABRICATOR_SENDGRID_APIKEY
+	fi
+fi
 
 # Installation
 if [ -z "$PHABRICATOR_NO_INSTALL" ]; then