diff --git a/crates/smtp/src/inbound/auth.rs b/crates/smtp/src/inbound/auth.rs
index 0b70403d..0ba7be49 100644
--- a/crates/smtp/src/inbound/auth.rs
+++ b/crates/smtp/src/inbound/auth.rs
@@ -51,7 +51,7 @@ impl<T: SessionStream> Session<T> {
         if response.is_empty() {
             match (token.mechanism, &token.credentials) {
                 (AUTH_PLAIN | AUTH_XOAUTH2 | AUTH_OAUTHBEARER, _) => {
-                    self.write(b"334 Go ahead.\r\n").await?;
+                    self.write(b"334 \r\n").await?;
                     return Ok(true);
                 }
                 (