diff --git a/src/auth.rs b/src/auth.rs
index 697eff3..31b8206 100644
--- a/src/auth.rs
+++ b/src/auth.rs
@@ -24,10 +24,18 @@ use crate::login::ArcLoginProvider;
 /// S: DONE
 /// C: VERSION	1	2
 /// C: CPID	1
+///
 /// C: AUTH	2	PLAIN	service=smtp	
 /// S: CONT	2	
 /// C: CONT	2   base64stringFollowingRFC4616==	
 /// S: OK	2	user=alice@example.tld
+///
+/// C: AUTH	42	LOGIN	service=smtp
+/// S: CONT	42	VXNlcm5hbWU6
+/// C: CONT	42	b64User
+/// S: CONT	42	UGFzc3dvcmQ6
+/// C: CONT	42	b64Pass
+/// S: FAIL	42	user=alice
 /// ```
 ///
 /// ## RFC References
@@ -698,6 +706,44 @@ fn lf_enc(out: &mut BytesMut) {
     out.put(&[0x0A][..])
 }
 
+impl Encode for Mechanism {
+    fn encode(&self, out: &mut BytesMut) -> Result<()> {
+        match self {
+            Self::Plain => out.put(&b"PLAIN"[..]),
+            Self::Login => out.put(&b"LOGIN"[..]),
+        }
+        Ok(())
+    }
+}
+
+impl Encode for MechanismParameters {
+    fn encode(&self, out: &mut BytesMut) -> Result<()> {
+        match self {
+            Self::Anonymous => out.put(&b"anonymous"[..]),
+            Self::PlainText => out.put(&b"plaintext"[..]),
+            Self::Dictionary => out.put(&b"dictionary"[..]),
+            Self::Active => out.put(&b"active"[..]),
+            Self::ForwardSecrecy => out.put(&b"forward-secrecy"[..]),
+            Self::MutualAuth => out.put(&b"mutual-auth"[..]),
+            Self::Private => out.put(&b"private"[..]),
+        }
+        Ok(())
+    }
+}
+
+
+impl Encode for FailCode {
+    fn encode(&self, out: &mut BytesMut) -> Result<()> {
+        match self {
+            Self::TempFail => out.put(&b"temp_fail"[..]),
+            Self::AuthzFail => out.put(&b"authz_fail"[..]),
+            Self::UserDisabled => out.put(&b"user_disabled"[..]),
+            Self::PassExpired => out.put(&b"pass_expired"[..]),
+        };
+        Ok(())
+    }
+}
+
 impl Encode for ServerCommand {
     fn encode(&self, out: &mut BytesMut) -> Result<()> {
         match self {
@@ -709,14 +755,85 @@ impl Encode for ServerCommand {
                 out.put(minor.to_string().as_bytes());
                 lf_enc(out);
             },
-            Self::Spid(v) => unimplemented!(),
-            Self::Cuid(v) => unimplemented!(),
-            Self::Mech { kind, parameters } => unimplemented!(),
-            Self::Cookie(v) => unimplemented!(),
-            Self::Done => unimplemented!(),
-            Self::Cont { id, data } => unimplemented!(),
-            Self::Ok { id, user_id, extra_parameters } => unimplemented!(),
-            Self::Fail {id, user_id, code, extra_parameters } => unimplemented!(),
+            Self::Spid(pid) => {
+                out.put(&b"SPID"[..]);
+                tab_enc(out);
+                out.put(pid.to_string().as_bytes());
+                lf_enc(out);
+            },
+            Self::Cuid(pid) => {
+                out.put(&b"CUID"[..]);
+                tab_enc(out);
+                out.put(pid.to_string().as_bytes());
+                lf_enc(out);
+            },
+            Self::Cookie(cval) => {
+                out.put(&b"COOKIE"[..]);
+                tab_enc(out);
+                out.put(hex::encode(cval).as_bytes()); 
+                lf_enc(out);
+
+            },
+            Self::Mech { kind, parameters } => {
+                out.put(&b"MECH"[..]);
+                tab_enc(out);
+                kind.encode(out)?;
+                for p in parameters.iter() {
+                    tab_enc(out);
+                    p.encode(out)?;
+                }
+                lf_enc(out);
+            },
+            Self::Done => {
+                out.put(&b"DONE"[..]);
+                lf_enc(out);
+            },
+            Self::Cont { id, data } => {
+                out.put(&b"CONT"[..]);
+                tab_enc(out);
+                out.put(id.to_string().as_bytes());
+                if let Some(rdata) = data {
+                    tab_enc(out);
+                    let b64 = base64::engine::general_purpose::STANDARD.encode(rdata);
+                    out.put(b64.as_bytes());
+                }
+                lf_enc(out);
+            },
+            Self::Ok { id, user_id, extra_parameters } => {
+                out.put(&b"OK"[..]);
+                tab_enc(out);
+                out.put(id.to_string().as_bytes());
+                if let Some(user) = user_id {
+                    tab_enc(out);
+                    out.put(&b"user="[..]);
+                    out.put(user.as_bytes());
+                }
+                for p in extra_parameters.iter() {
+                    tab_enc(out);
+                    out.put(&p[..]);
+                }
+                lf_enc(out);
+            },
+            Self::Fail {id, user_id, code, extra_parameters } => {
+                out.put(&b"FAIL"[..]);
+                tab_enc(out);
+                out.put(id.to_string().as_bytes());
+                if let Some(user) = user_id {
+                    tab_enc(out);
+                    out.put(&b"user="[..]);
+                    out.put(user.as_bytes());
+                }
+                if let Some(code_val) = code {
+                    tab_enc(out);
+                    out.put(&b"code="[..]);
+                    code_val.encode(out)?;
+                }
+                for p in extra_parameters.iter() {
+                    tab_enc(out);
+                    out.put(&p[..]);
+                }
+                lf_enc(out);
+            },
         }
         Ok(())
     }