diff --git a/protocol.go b/protocol.go
index d0d68cd..16117ac 100644
--- a/protocol.go
+++ b/protocol.go
@@ -28,10 +28,32 @@ func parseLine(line string) (cmd command) {
 	cmd.fields = strings.Fields(line)
 
 	if len(cmd.fields) > 0 {
+
 		cmd.action = strings.ToUpper(cmd.fields[0])
+
 		if len(cmd.fields) > 1 {
+
+			// Account for some clients breaking the standard and having
+			// an extra whitespace after the ':' character. Example:
+			//
+			// MAIL FROM: <christian@technobabble.dk>
+			//
+			// Should be:
+			//
+			// MAIL FROM:<christian@technobabble.dk>
+			//
+			// Thus, we add a check if the second field ends with ':'
+			// and appends the rest of the third field.
+
+			if cmd.fields[1][len(cmd.fields[1])-1] == ':' && len(cmd.fields) > 2 {
+				cmd.fields[1] = cmd.fields[1] + cmd.fields[2]
+				cmd.fields = cmd.fields[0:2]
+			}
+
 			cmd.params = strings.Split(cmd.fields[1], ":")
+
 		}
+
 	}
 
 	return
diff --git a/protocol_test.go b/protocol_test.go
new file mode 100644
index 0000000..aa04b70
--- /dev/null
+++ b/protocol_test.go
@@ -0,0 +1,83 @@
+package smtpd
+
+import "testing"
+
+func TestParseLine(t *testing.T) {
+
+	cmd := parseLine("HELO hostname")
+	if cmd.action != "HELO" {
+		t.Fatalf("unexpected action: %s", cmd.action)
+	}
+
+	if len(cmd.fields) != 2 {
+		t.Fatalf("unexpected fields length: %d", len(cmd.fields))
+	}
+
+	if len(cmd.params) != 1 {
+		t.Fatalf("unexpected params length: %d", len(cmd.params))
+	}
+
+	if cmd.params[0] != "hostname" {
+		t.Fatalf("unexpected value for param 0: %v", cmd.params[0])
+	}
+
+	cmd = parseLine("DATA")
+	if cmd.action != "DATA" {
+		t.Fatalf("unexpected action: %s", cmd.action)
+	}
+
+	if len(cmd.fields) != 1 {
+		t.Fatalf("unexpected fields length: %d", len(cmd.fields))
+	}
+
+	if cmd.params != nil {
+		t.Fatalf("unexpected params: %v", cmd.params)
+	}
+
+	cmd = parseLine("MAIL FROM:<christian@technobabble.dk>")
+	if cmd.action != "MAIL" {
+		t.Fatalf("unexpected action: %s", cmd.action)
+	}
+
+	if len(cmd.fields) != 2 {
+		t.Fatalf("unexpected fields length: %d", len(cmd.fields))
+	}
+
+	if len(cmd.params) != 2 {
+		t.Fatalf("unexpected params length: %d", len(cmd.params))
+	}
+
+	if cmd.params[0] != "FROM" {
+		t.Fatalf("unexpected value for param 0: %v", cmd.params[0])
+	}
+
+	if cmd.params[1] != "<christian@technobabble.dk>" {
+		t.Fatalf("unexpected value for param 1: %v", cmd.params[1])
+	}
+
+}
+
+func TestParseLineMailformedMAILFROM(t *testing.T) {
+
+	cmd := parseLine("MAIL FROM: <christian@technobabble.dk>")
+	if cmd.action != "MAIL" {
+		t.Fatalf("unexpected action: %s", cmd.action)
+	}
+
+	if len(cmd.fields) != 2 {
+		t.Fatalf("unexpected fields length: %d", len(cmd.fields))
+	}
+
+	if len(cmd.params) != 2 {
+		t.Fatalf("unexpected params length: %d", len(cmd.params))
+	}
+
+	if cmd.params[0] != "FROM" {
+		t.Fatalf("unexpected value for param 0: %v", cmd.params[0])
+	}
+
+	if cmd.params[1] != "<christian@technobabble.dk>" {
+		t.Fatalf("unexpected value for param 1: %v", cmd.params[1])
+	}
+
+}
diff --git a/smtpd_test.go b/smtpd_test.go
index 3f6a2a0..57bccba 100644
--- a/smtpd_test.go
+++ b/smtpd_test.go
@@ -1160,3 +1160,34 @@ func TestErrors(t *testing.T) {
 	}
 
 }
+
+func TestMailformedMAILFROM(t *testing.T) {
+
+	addr, closer := runserver(t, &smtpd.Server{
+		SenderChecker: func(peer smtpd.Peer, addr string) error {
+			if addr != "christian@technobabble.dk" {
+				return smtpd.Error{Code: 502, Message: "Denied"}
+			}
+			return nil
+		},
+	})
+
+	defer closer()
+
+	c, err := smtp.Dial(addr)
+	if err != nil {
+		t.Fatalf("Dial failed: %v", err)
+	}
+
+	if err := c.Hello("localhost"); err != nil {
+		t.Fatalf("HELO failed: %v", err)
+	}
+
+	if err := cmd(c.Text, 250, "MAIL FROM: <christian@technobabble.dk>"); err != nil {
+		t.Fatalf("MAIL FROM failed with extra whitespace: %v", err)
+	}
+
+	if err := c.Quit(); err != nil {
+		t.Fatalf("Quit failed: %v", err)
+	}
+}