Added configurable smtp timeout.

- Added config option for smtp timeout
 - Lowered default timeout to 15 seconds instead of default 60.

.env.template

@@ -157,3 +157,4 @@
 # SMTP_USERNAME=username
 # SMTP_PASSWORD=password
 # SMTP_AUTH_MECHANISM="Plain"
+# SMTP_TIMEOUT=15

src/config.rs

@@ -350,6 +350,8 @@ make_config! {
         smtp_password:          Pass,   true,   option;
         /// Json form auth mechanism |> Defaults for ssl is "Plain" and "Login" and nothing for non-ssl connections. Possible values: ["Plain", "Login", "Xoauth2"]
         smtp_auth_mechanism:    String, true,   option;
+        /// SMTP connection timeout |> Number of seconds when to stop trying to connect to the SMTP server
+        smtp_timeout:           u64,     true,   def,     15;
     },
 
     /// Email 2FA Settings

src/mail.rs

@@ -33,6 +33,8 @@ fn mailer() -> SmtpTransport {
         ClientSecurity::None
     };
 
+    use std::time::Duration;
+
     let smtp_client = SmtpClient::new((host.as_str(), CONFIG.smtp_port()), client_security).unwrap();
 
     let smtp_client = match (&CONFIG.smtp_username(), &CONFIG.smtp_password()) {
@@ -53,6 +55,7 @@ fn mailer() -> SmtpTransport {
 
     smtp_client
         .smtp_utf8(true)
+        .timeout(Some(Duration::from_secs(CONFIG.smtp_timeout())))
         .connection_reuse(ConnectionReuseParameters::NoReuse)
         .transport()
 }