Added setting for SMTP hello command.

src/backend/mail.rs

@@ -17,6 +17,7 @@ cfg_if! { if #[cfg(feature = "ssr")] {
     use lettre::{AsyncSmtpTransport, AsyncFileTransport, AsyncTransport, Tokio1Executor};
     use lettre::transport::smtp::client::{Tls, TlsParameters};
     use lettre::transport::smtp::authentication::Credentials;
+    use lettre::transport::smtp::extension::ClientId;
     use std::ops::Add;
 
     pub async fn message_for_type(msg_type: &MessageType, pool: &PgPool) -> Result<Message, Error> {
@@ -137,6 +138,11 @@ cfg_if! { if #[cfg(feature = "ssr")] {
                     } else {
                         transport
                     };
+                    let transport = if let Some(hello) = self.hello_name() {
+                        transport.hello_name(ClientId::Domain(hello.to_string()))
+                    } else {
+                        transport
+                    };
                     if self.user().is_some() && self.password().is_some() {
                         let cred = Credentials::new(self.user().clone().unwrap(), self.password().clone().unwrap());
                         transport.credentials(cred).build().send(msg.build_mail(self.from().to_string())?).await?;