Index: src/mail.rs
==================================================================
--- src/mail.rs	
+++ src/mail.rs	
@@ -106,11 +106,11 @@
 			address,
 		})
 	}
 
 	/// Returns id for provided email address
-	fn get_id (&self, name_str: &str) -> Result<&ChatPeerId> {
+	pub fn get_id (&self, name_str: &str) -> Result<&ChatPeerId> {
 		// here we need to store String locally to borrow it after
 		let mut link = name_str;
 		let name: String;
 		if let Some(caps) = self.address.captures(link) {
 			name = caps["name"].to_string();

ADDED   tests/mail.rs
Index: tests/mail.rs
==================================================================
--- /dev/null	
+++ tests/mail.rs	
@@ -0,0 +1,49 @@
+use smtp2tg::mail::MailServer;
+
+use stacked_errors::{
+	Result,
+	StackableErr,
+};
+
+use tgbot::types::ChatPeerId;
+/// Builds a `MailServer` purely from an in-memory TOML source, no
+/// network access is performed while constructing it.
+fn build_server () -> Result<MailServer> {
+	let settings = config::Config::builder()
+		.add_source(config::File::from_str(r#"
+			api_key = "test-api-key"
+			api_gateway = "https://api.telegram.org"
+			default = 0
+			unknown = "relay"
+			fields = ["date", "from", "subject"]
+			domains = ["example.com"]
+
+			[recipients]
+			"someone@example.com" = 1
+			"root" = -1
+		"#, config::FileFormat::Toml))
+		.build()
+		.stack()?;
+	MailServer::new(settings)
+}
+
+#[test]
+fn get_id_returns_configured_recipient_for_full_address () -> Result<()> {
+	let server = build_server()?;
+	assert_eq!(*server.get_id("someone@example.com")?, ChatPeerId::from(1));
+	Ok(())
+}
+
+#[test]
+fn get_id_returns_configured_recipient_for_bare_name () -> Result<()> {
+	let server = build_server()?;
+	assert_eq!(*server.get_id("root")?, ChatPeerId::from(-1));
+	Ok(())
+}
+
+#[test]
+fn get_id_falls_back_to_default_for_unknown_address () -> Result<()> {
+	let server = build_server()?;
+	assert_eq!(*server.get_id("unknown@example.com")?, ChatPeerId::from(0));
+	Ok(())
+}