diff --git a/Cargo.lock b/Cargo.lock
index 2f339d2..4beb964 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -62,24 +62,24 @@ dependencies = [
 
 [[package]]
 name = "hermit-abi"
-version = "0.1.18"
+version = "0.1.19"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "322f4de77956e22ed0e5032c359a0f1273f1f7f0d79bfa3b8ffbc730d7fbcc5c"
+checksum = "62b467343b94ba476dcb2500d242dadbb39557df889310ac77c5d99100aaac33"
 dependencies = [
  "libc",
 ]
 
 [[package]]
 name = "ipnet"
-version = "2.3.0"
+version = "2.3.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "47be2f14c678be2fdcab04ab1171db51b2762ce6f0a8ee87c8dd4a04ed216135"
+checksum = "68f2d64f2edebec4ce84ad108148e67e1064789bee435edc5b60ad398714a3a9"
 
 [[package]]
 name = "libc"
-version = "0.2.94"
+version = "0.2.98"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "18794a8ad5b29321f790b55d93dfba91e125cb1a9edbd4f8e3150acc771c1a5e"
+checksum = "320cfe77175da3a483efed4bc0adc1968ca050b098ce4f2f1c13a56626128790"
 
 [[package]]
 name = "milter"
@@ -136,9 +136,9 @@ dependencies = [
 
 [[package]]
 name = "once_cell"
-version = "1.7.2"
+version = "1.8.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "af8b08b04175473088b46763e51ee54da5f9a164bc162f615b91bc179dbf15a3"
+checksum = "692fcb63b64b1758029e0a96ee63e049ce8c5948587f2f7208df04625e5f6b56"
 
 [[package]]
 name = "pkg-config"
@@ -148,9 +148,9 @@ checksum = "3831453b3449ceb48b6d9c7ad7c96d5ea673e9b470a1dc578c2ce6521230884c"
 
 [[package]]
 name = "proc-macro2"
-version = "1.0.26"
+version = "1.0.28"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "a152013215dca273577e18d2bf00fa862b89b24169fb78c4c95aeb07992c9cec"
+checksum = "5c7ed8b8c7b886ea3ed7dde405212185f423ab44682667c8c6dd14aa1d9f6612"
 dependencies = [
  "unicode-xid",
 ]
@@ -184,9 +184,9 @@ checksum = "8ea5119cdb4c55b55d432abb513a0429384878c15dde60cc77b1c99de1a95a6a"
 
 [[package]]
 name = "syn"
-version = "1.0.72"
+version = "1.0.74"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "a1e8cdbefb79a9a5a65e0db8b47b723ee907b7c7f8496c76a1770b5c310bab82"
+checksum = "1873d832550d4588c3dbc20f01361ab00bfe741048f71e3fecf145a7cc18b29c"
 dependencies = [
  "proc-macro2",
  "quote",
diff --git a/src/client.rs b/src/client.rs
index ea16a71..4248c48 100644
--- a/src/client.rs
+++ b/src/client.rs
@@ -186,18 +186,18 @@ impl Client {
         date_time: &str,
     ) -> Result<()> {
         let buf = format!(
-            "Received: from {} ({})\r\n\
-             \tby {} ({}) with {} id {};\r\n\
-             \t{}\r\n\
-             \t(envelope-from {})\r\n",
-            helo_host,
-            client_name_addr,
-            my_hostname,
-            mta,
-            if tls { "ESMTPS" } else { "ESMTP" },
-            queue_id,
-            date_time,
-            self.sender
+            "Received: from {helo} ({client})\r\n\
+             \tby {hostname} ({mta}) with {proto} id {id};\r\n\
+             \t{date_time}\r\n\
+             \t(envelope-from {sender})\r\n",
+            helo = helo_host,
+            client = client_name_addr,
+            hostname = my_hostname,
+            mta = mta,
+            proto = if tls { "ESMTPS" } else { "ESMTP" },
+            id = queue_id,
+            date_time = date_time,
+            sender = self.sender
         );
 
         self.process.writer().write_all(buf.as_bytes())?;