diff --git a/backend/windmill-api/src/settings.rs b/backend/windmill-api/src/settings.rs
index 4747775721..63be49e1b9 100644
--- a/backend/windmill-api/src/settings.rs
+++ b/backend/windmill-api/src/settings.rs
@@ -56,9 +56,16 @@ pub async fn test_email(
     require_super_admin(&db, &authed.email).await?;
     let smtp = test_email.smtp;
     let to = test_email.to;
-    let client = SmtpClientBuilder::new(smtp.host, smtp.port)
-        .implicit_tls(smtp.tls_implicit)
-        .credentials((smtp.username, smtp.password));
+    let client = SmtpClientBuilder::new(smtp.host, smtp.port).implicit_tls(smtp.tls_implicit);
+    let client = if let (Some(username), Some(password)) = (smtp.username, smtp.password) {
+        if !username.is_empty() {
+            client.credentials((username, password))
+        } else {
+            client
+        }
+    } else {
+        client
+    };
     let message = MessageBuilder::new()
         .from(("Windmill", smtp.from.as_str()))
         .to(to.clone())
diff --git a/backend/windmill-api/src/users.rs b/backend/windmill-api/src/users.rs
index 0ecc5820b1..fddd9b9ebd 100644
--- a/backend/windmill-api/src/users.rs
+++ b/backend/windmill-api/src/users.rs
@@ -1665,9 +1665,16 @@ pub fn send_email_if_possible(subject: &str, content: &str, to: &str) {
 
 pub async fn send_email_if_possible_intern(subject: &str, content: &str, to: &str) -> Result<()> {
     if let Some(smtp) = SERVER_CONFIG.read().await.smtp.clone() {
-        let client = SmtpClientBuilder::new(smtp.host, smtp.port)
-            .implicit_tls(smtp.tls_implicit)
-            .credentials((smtp.username, smtp.password));
+        let client = SmtpClientBuilder::new(smtp.host, smtp.port).implicit_tls(smtp.tls_implicit);
+        let client = if let (Some(username), Some(password)) = (smtp.username, smtp.password) {
+            if !username.is_empty() {
+                client.credentials((username, password))
+            } else {
+                client
+            }
+        } else {
+            client
+        };
         let message = MessageBuilder::new()
             .from(("Windmill", smtp.from.as_str()))
             .to(to)
diff --git a/backend/windmill-common/src/server.rs b/backend/windmill-common/src/server.rs
index 6591377f63..a6b12ca7b6 100644
--- a/backend/windmill-common/src/server.rs
+++ b/backend/windmill-common/src/server.rs
@@ -5,8 +5,8 @@ use crate::{error, DB};
 #[derive(Serialize, Deserialize, PartialEq, Clone, Debug)]
 pub struct Smtp {
     pub host: String,
-    pub username: String,
-    pub password: String,
+    pub username: Option<String>,
+    pub password: Option<String>,
     pub port: u16,
     pub from: String,
     pub tls_implicit: bool,
@@ -33,7 +33,7 @@ pub async fn load_server_config(db: &DB) -> error::Result<ServerConfig> {
             .flatten()
             .unwrap_or_default();
 
-    let config_smtp = if let (Some(host), Some(username), Some(password)) =
+    let config_smtp = if let (Some(host), username, password) =
         (config.smtp_host, config.smtp_username, config.smtp_password)
     {
         Some(Smtp {
@@ -50,7 +50,7 @@ pub async fn load_server_config(db: &DB) -> error::Result<ServerConfig> {
         None
     };
     let smtp = config_smtp.or(
-        if let (Some(host), Some(username), Some(password)) = (
+        if let (Some(host), username, password) = (
             std::env::var("SMTP_HOST").ok(),
             std::env::var("SMTP_USERNAME").ok(),
             std::env::var("SMTP_PASSWORD").ok(),