diff --git a/Cargo.lock b/Cargo.lock
index f9537aac..bd94774c 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -14,6 +14,15 @@ version = "0.4.7"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "739f4a8db6605981345c5654f3a85b056ce52f37a39d34da03f25bf2151ea16e"
 
+[[package]]
+name = "aho-corasick"
+version = "0.7.15"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7404febffaa47dac81aa44dba71523c9d069b1bdc50a77db41195149e17f68e5"
+dependencies = [
+ "memchr",
+]
+
 [[package]]
 name = "arrayref"
 version = "0.3.6"
@@ -1117,6 +1126,7 @@ dependencies = [
  "pcre2",
  "proc-macro2",
  "quote 1.0.8",
+ "regex",
  "serde",
  "serde_derive",
  "serde_json",
@@ -1673,6 +1683,23 @@ dependencies = [
  "rust-argon2",
 ]
 
+[[package]]
+name = "regex"
+version = "1.4.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "2a26af418b574bd56588335b3a3659a65725d4e636eb1016c2f9e3b38c7cc759"
+dependencies = [
+ "aho-corasick",
+ "memchr",
+ "regex-syntax",
+]
+
+[[package]]
+name = "regex-syntax"
+version = "0.6.25"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f497285884f3fcff424ffc933e56d7cbca511def0c9831a7f9b5f6153e3cc89b"
+
 [[package]]
 name = "remove_dir_all"
 version = "0.5.3"
diff --git a/Cargo.toml b/Cargo.toml
index bc530354..b9563d2a 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -54,7 +54,7 @@ futures = "0.3.5"
 async-task = "3.0.0"
 num_cpus = "1.12.0"
 flate2 = { version = "1.0.16", optional = true }
- 
+
 [target.'cfg(target_os="linux")'.dependencies]
 notify-rust = { version = "^4", optional = true }
 
@@ -64,6 +64,9 @@ quote = "^1.0"
 proc-macro2 = "1.0.18"
 flate2 = { version = "1.0.16", optional = true }
 
+[dev-dependencies]
+regex = "1"
+
 [profile.release]
 lto = "fat"
 codegen-units = 1
diff --git a/docs/meli.conf.5 b/docs/meli.conf.5
index 4d8fc741..99a265af 100644
--- a/docs/meli.conf.5
+++ b/docs/meli.conf.5
@@ -77,7 +77,7 @@ example configuration
 [accounts.account-name]
 root_mailbox = "/path/to/root/folder"
 format = "Maildir"
-index_style = "Compact"
+listing.index_style = "Compact"
 identity="email@example.com"
 subscribed_mailboxes = ["folder", "folder/Sent"] # or [ "*", ] for all mailboxes
 display_name = "Name"
@@ -93,7 +93,7 @@ display_name = "Name"
 [accounts.mbox]
 root_mailbox = "/var/mail/username"
 format = "mbox"
-index_style = "Compact"
+listing.index_style = "Compact"
 identity="username@hostname.local"
 composing.send_mail = { hostname = "localhost", port = 25, auth = { type = "none" }, security = { type = "none" } }
 
@@ -138,8 +138,6 @@ The glob wildcard
 can be used to match every mailbox name and path.
 .It Ic identity Ar String
 Your e-mail address that is inserted in the From: headers of outgoing mail.
-.It Ic index_style Ar String
-Sets the way mailboxes are displayed.
 .El
 .TS
 allbox tab(:);
diff --git a/docs/samples/sample-config.toml b/docs/samples/sample-config.toml
index 58ff1134..2b2e5e92 100644
--- a/docs/samples/sample-config.toml
+++ b/docs/samples/sample-config.toml
@@ -11,7 +11,7 @@
 #[accounts.account-name]
 #root_mailbox = "/path/to/root/mailbox"
 #format = "Maildir"
-#index_style = "Conversations" # or [plain, threaded, compact]
+#listing.index_style = "Conversations" # or [plain, threaded, compact]
 #identity="email@example.com"
 #display_name = "Name"
 #subscribed_mailboxes = ["INBOX", "INBOX/Sent", "INBOX/Drafts", "INBOX/Junk"]
@@ -26,7 +26,7 @@
 #[accounts.mbox]
 #root_mailbox = "/var/mail/username"
 #format = "mbox"
-#index_style = "Compact"
+#listing.index_style = "Compact"
 #identity="username@hostname.local"
 #
 ## Setting up an IMAP account
@@ -36,10 +36,10 @@
 #server_hostname="mail.example.com"
 #server_password="pha2hiLohs2eeeish2phaii1We3ood4chakaiv0hien2ahie3m"
 #server_username="username@example.com"
-#server_port="993" # imaps
+##server_port="993" # imaps
 #server_port="143" # STARTTLS
 #use_starttls=true #optional
-#index_style = "Conversations"
+#listing.index_style = "Conversations"
 #identity = "username@example.com"
 #display_name = "Name Name"
 ### match every mailbox:
@@ -51,7 +51,7 @@
 #[accounts.notmuch]
 #root_mailbox = "/path/to/folder" # where .notmuch/ directory is located
 #format = "notmuch"
-#index_style = "conversations"
+#listing.index_style = "conversations"
 #identity="username@example.com"
 #display_name = "Name Name"
 #  # notmuch mailboxes are virtual, they are defined by their alias and the notmuch query that corresponds to their content.
@@ -68,7 +68,7 @@
 #server_password="password"
 #server_username="username@gmail.com"
 #server_port="993"
-#index_style = "Conversations"
+#listing.index_style = "Conversations"
 #identity = "username@gmail.com"
 #display_name = "Name Name"
 ### match every mailbox:
diff --git a/melib/src/backends.rs b/melib/src/backends.rs
index 57ef9feb..f50f1816 100644
--- a/melib/src/backends.rs
+++ b/melib/src/backends.rs
@@ -97,7 +97,7 @@ pub struct Backends {
 
 pub struct Backend {
     pub create_fn: Box<dyn Fn() -> BackendCreator>,
-    pub validate_conf_fn: Box<dyn Fn(&AccountSettings) -> Result<()>>,
+    pub validate_conf_fn: Box<dyn Fn(&mut AccountSettings) -> Result<()>>,
 }
 
 impl Default for Backends {
@@ -200,7 +200,7 @@ impl Backends {
         self.map.insert(key, backend);
     }
 
-    pub fn validate_config(&self, key: &str, s: &AccountSettings) -> Result<()> {
+    pub fn validate_config(&self, key: &str, s: &mut AccountSettings) -> Result<()> {
         (self
             .map
             .get(key)
diff --git a/melib/src/backends/imap.rs b/melib/src/backends/imap.rs
index b7c947e1..b9b5bca3 100644
--- a/melib/src/backends/imap.rs
+++ b/melib/src/backends/imap.rs
@@ -1500,12 +1500,12 @@ impl ImapType {
         Ok(mailboxes)
     }
 
-    pub fn validate_config(s: &AccountSettings) -> Result<()> {
+    pub fn validate_config(s: &mut AccountSettings) -> Result<()> {
         let mut keys: HashSet<&'static str> = Default::default();
         macro_rules! get_conf_val {
             ($s:ident[$var:literal]) => {{
                 keys.insert($var);
-                $s.extra.get($var).ok_or_else(|| {
+                $s.extra.remove($var).ok_or_else(|| {
                     MeliError::new(format!(
                         "Configuration error ({}): IMAP connection requires the field `{}` set",
                         $s.name.as_str(),
@@ -1516,9 +1516,9 @@ impl ImapType {
             ($s:ident[$var:literal], $default:expr) => {{
                 keys.insert($var);
                 $s.extra
-                    .get($var)
+                    .remove($var)
                     .map(|v| {
-                        <_>::from_str(v).map_err(|e| {
+                        <_>::from_str(&v).map_err(|e| {
                             MeliError::new(format!(
                                 "Configuration error ({}): Invalid value for field `{}`: {}\n{}",
                                 $s.name.as_str(),
diff --git a/melib/src/backends/jmap.rs b/melib/src/backends/jmap.rs
index b8848adc..8421d130 100644
--- a/melib/src/backends/jmap.rs
+++ b/melib/src/backends/jmap.rs
@@ -874,7 +874,34 @@ impl JmapType {
         }))
     }
 
-    pub fn validate_config(s: &AccountSettings) -> Result<()> {
+    pub fn validate_config(s: &mut AccountSettings) -> Result<()> {
+        macro_rules! get_conf_val {
+            ($s:ident[$var:literal]) => {
+                $s.extra.remove($var).ok_or_else(|| {
+                    MeliError::new(format!(
+                        "Configuration error ({}): JMAP connection requires the field `{}` set",
+                        $s.name.as_str(),
+                        $var
+                    ))
+                })
+            };
+            ($s:ident[$var:literal], $default:expr) => {
+                $s.extra
+                    .remove($var)
+                    .map(|v| {
+                        <_>::from_str(&v).map_err(|e| {
+                            MeliError::new(format!(
+                                "Configuration error ({}): Invalid value for field `{}`: {}\n{}",
+                                $s.name.as_str(),
+                                $var,
+                                v,
+                                e
+                            ))
+                        })
+                    })
+                    .unwrap_or_else(|| Ok($default))
+            };
+        }
         get_conf_val!(s["server_hostname"])?;
         get_conf_val!(s["server_username"])?;
         get_conf_val!(s["server_password"])?;
diff --git a/melib/src/backends/maildir/backend.rs b/melib/src/backends/maildir/backend.rs
index e515c2c1..84e4515b 100644
--- a/melib/src/backends/maildir/backend.rs
+++ b/melib/src/backends/maildir/backend.rs
@@ -1316,7 +1316,7 @@ impl MaildirType {
         Ok(())
     }
 
-    pub fn validate_config(s: &AccountSettings) -> Result<()> {
+    pub fn validate_config(s: &mut AccountSettings) -> Result<()> {
         let root_path = PathBuf::from(s.root_mailbox()).expand();
         if !root_path.exists() {
             return Err(MeliError::new(format!(
diff --git a/melib/src/backends/mbox.rs b/melib/src/backends/mbox.rs
index fbc3cbb4..5dad56fa 100644
--- a/melib/src/backends/mbox.rs
+++ b/melib/src/backends/mbox.rs
@@ -1339,7 +1339,34 @@ impl MboxType {
         Ok(Box::new(ret))
     }
 
-    pub fn validate_config(s: &AccountSettings) -> Result<()> {
+    pub fn validate_config(s: &mut AccountSettings) -> Result<()> {
+        macro_rules! get_conf_val {
+            ($s:ident[$var:literal]) => {
+                $s.extra.remove($var).ok_or_else(|| {
+                    MeliError::new(format!(
+                        "Configuration error ({}): mbox backend requires the field `{}` set",
+                        $s.name.as_str(),
+                        $var
+                    ))
+                })
+            };
+            ($s:ident[$var:literal], $default:expr) => {
+                $s.extra
+                    .remove($var)
+                    .map(|v| {
+                        <_>::from_str(&v).map_err(|e| {
+                            MeliError::new(format!(
+                                "Configuration error ({}): Invalid value for field `{}`: {}\n{}",
+                                $s.name.as_str(),
+                                $var,
+                                v,
+                                e
+                            ))
+                        })
+                    })
+                    .unwrap_or_else(|| Ok($default))
+            };
+        }
         let path = Path::new(s.root_mailbox.as_str()).expand();
         if !path.exists() {
             return Err(MeliError::new(format!(
diff --git a/melib/src/backends/nntp.rs b/melib/src/backends/nntp.rs
index bf7fd0e0..342ddca9 100644
--- a/melib/src/backends/nntp.rs
+++ b/melib/src/backends/nntp.rs
@@ -654,12 +654,12 @@ impl NntpType {
         Ok(())
     }
 
-    pub fn validate_config(s: &AccountSettings) -> Result<()> {
+    pub fn validate_config(s: &mut AccountSettings) -> Result<()> {
         let mut keys: HashSet<&'static str> = Default::default();
         macro_rules! get_conf_val {
     ($s:ident[$var:literal]) => {{
         keys.insert($var);
-        $s.extra.get($var).ok_or_else(|| {
+        $s.extra.remove($var).ok_or_else(|| {
             MeliError::new(format!(
                 "Configuration error ({}): NNTP connection requires the field `{}` set",
                 $s.name.as_str(),
@@ -670,9 +670,9 @@ impl NntpType {
     ($s:ident[$var:literal], $default:expr) => {{
         keys.insert($var);
         $s.extra
-            .get($var)
+            .remove($var)
             .map(|v| {
-                <_>::from_str(v).map_err(|e| {
+                <_>::from_str(&v).map_err(|e| {
                     MeliError::new(format!(
                         "Configuration error ({}) NNTP: Invalid value for field `{}`: {}\n{}",
                         $s.name.as_str(),
diff --git a/melib/src/backends/notmuch.rs b/melib/src/backends/notmuch.rs
index fa7c3406..7bdb3fa0 100644
--- a/melib/src/backends/notmuch.rs
+++ b/melib/src/backends/notmuch.rs
@@ -372,7 +372,7 @@ impl NotmuchDb {
         }))
     }
 
-    pub fn validate_config(s: &AccountSettings) -> Result<()> {
+    pub fn validate_config(s: &mut AccountSettings) -> Result<()> {
         let path = Path::new(s.root_mailbox.as_str()).expand();
         if !path.exists() {
             return Err(MeliError::new(format!(
@@ -381,8 +381,8 @@ impl NotmuchDb {
                 s.name()
             )));
         }
-        for (k, f) in s.mailboxes.iter() {
-            if f.extra.get("query").is_none() {
+        for (k, f) in s.mailboxes.iter_mut() {
+            if f.extra.remove("query").is_none() {
                 return Err(MeliError::new(format!(
                     "notmuch mailbox configuration entry \"{}\" should have a \"query\" value set.",
                     k
diff --git a/src/bin.rs b/src/bin.rs
index 750cf292..37689757 100644
--- a/src/bin.rs
+++ b/src/bin.rs
@@ -223,7 +223,7 @@ fn run_app(opt: Opt) -> Result<()> {
             } else {
                 crate::conf::get_config_file()?
             };
-            conf::FileSettings::validate(config_path, true)?; // TODO: test for tty/interaction
+            conf::FileSettings::validate(config_path, true, false)?; // TODO: test for tty/interaction
             return Ok(());
         }
         Some(SubCommand::CreateConfig { path }) => {
diff --git a/src/conf.rs b/src/conf.rs
index 09bf7bb7..b92cf79b 100644
--- a/src/conf.rs
+++ b/src/conf.rs
@@ -350,10 +350,10 @@ impl FileSettings {
             return Err(MeliError::new("No configuration file found."));
         }
 
-        FileSettings::validate(config_path, true)
+        FileSettings::validate(config_path, true, false)
     }
 
-    pub fn validate(path: PathBuf, interactive: bool) -> Result<Self> {
+    pub fn validate(path: PathBuf, interactive: bool, clear_extras: bool) -> Result<Self> {
         let s = pp::pp(&path)?;
         let map: toml::map::Map<String, toml::value::Value> = toml::from_str(&s).map_err(|e| {
             MeliError::new(format!(
@@ -391,7 +391,7 @@ This is required so that you don't accidentally start meli and find out later th
                                 err
                             ))
                         })?;
-                    return FileSettings::validate(path, interactive);
+                    return FileSettings::validate(path, interactive, clear_extras);
                 }
             }
             return Err(MeliError::new(format!(
@@ -439,7 +439,7 @@ This is required so that you don't accidentally start meli and find out later th
         }
 
         s.terminal.themes.validate()?;
-        for (name, acc) in &s.accounts {
+        for (name, acc) in s.accounts.iter_mut() {
             let FileAccount {
                 root_mailbox,
                 format,
@@ -456,7 +456,7 @@ This is required so that you don't accidentally start meli and find out later th
             } = acc.clone();
 
             let lowercase_format = format.to_lowercase();
-            let s = AccountSettings {
+            let mut s = AccountSettings {
                 name: name.to_string(),
                 root_mailbox,
                 format: format.clone(),
@@ -471,7 +471,16 @@ This is required so that you don't accidentally start meli and find out later th
                     .collect(),
                 extra: extra.into_iter().collect(),
             };
-            backends.validate_config(&lowercase_format, &s)?;
+            backends.validate_config(&lowercase_format, &mut s)?;
+            if !s.extra.is_empty() {
+                return Err(MeliError::new(format!(
+                    "Unrecognised configuration values: {:?}",
+                    s.extra
+                )));
+            }
+            if clear_extras {
+                acc.extra.clear();
+            }
         }
 
         Ok(s)
@@ -1136,7 +1145,7 @@ fn test_config_parse() {
 [accounts.account-name]
 root_mailbox = "/path/to/root/mailbox"
 format = "Maildir"
-index_style = "Conversations" # or [plain, threaded, compact]
+listing.index_style = "Conversations" # or [plain, threaded, compact]
 identity="email@example.com"
 display_name = "Name"
 subscribed_mailboxes = ["INBOX", "INBOX/Sent", "INBOX/Drafts", "INBOX/Junk"]
@@ -1151,11 +1160,25 @@ subscribed_mailboxes = ["INBOX", "INBOX/Sent", "INBOX/Drafts", "INBOX/Junk"]
 [accounts.mbox]
 root_mailbox = "/var/mail/username"
 format = "mbox"
+listing.index_style = "Compact"
+identity="username@hostname.local"
+"#;
+
+    const EXTRA_CONFIG: &str = r#"
+[accounts.mbox]
+root_mailbox = "/"
+format = "mbox"
 index_style = "Compact"
 identity="username@hostname.local"
+
+[composing]
+send_mail = '/bin/false'
 "#;
+
+    const EXAMPLE_CONFIG: &str = include_str!("../docs/samples/sample-config.toml");
+
     impl ConfigFile {
-        fn new() -> std::result::Result<Self, std::io::Error> {
+        fn new(content: &str) -> std::result::Result<Self, std::io::Error> {
             let mut f = fs::File::open("/dev/urandom")?;
             let mut buf = [0u8; 16];
             f.read_exact(&mut buf)?;
@@ -1169,7 +1192,7 @@ identity="username@hostname.local"
                 .create_new(true)
                 .append(true)
                 .open(&path)?;
-            file.write_all(TEST_CONFIG.as_bytes())?;
+            file.write_all(content.as_bytes())?;
             Ok(ConfigFile { path, file })
         }
     }
@@ -1180,13 +1203,46 @@ identity="username@hostname.local"
         }
     }
 
-    let mut new_file = ConfigFile::new().unwrap();
-    let err = FileSettings::validate(new_file.path.clone(), false).unwrap_err();
+    let mut new_file = ConfigFile::new(TEST_CONFIG).unwrap();
+    let err = FileSettings::validate(new_file.path.clone(), false, true).unwrap_err();
     assert!(err.details.as_ref().starts_with("You must set a global `composing` option. If you override `composing` in each account, you can use a dummy global like follows"));
     new_file
         .file
         .write_all("[composing]\nsend_mail = '/bin/false'\n".as_bytes())
         .unwrap();
-    let err = FileSettings::validate(new_file.path.clone(), false).unwrap_err();
+    let err = FileSettings::validate(new_file.path.clone(), false, true).unwrap_err();
     assert_eq!(err.details.as_ref(), "Configuration error (account-name): root_path `/path/to/root/mailbox` is not a valid directory.");
+
+    /* Test unrecognised configuration entries error */
+
+    let new_file = ConfigFile::new(EXTRA_CONFIG).unwrap();
+    let err = FileSettings::validate(new_file.path.clone(), false, true).unwrap_err();
+    assert_eq!(
+        err.details.as_ref(),
+        "Unrecognised configuration values: {\"index_style\": \"Compact\"}"
+    );
+
+    /* Test sample config */
+
+    let example_config = EXAMPLE_CONFIG.replace("\n#", "\n");
+    let re = regex::Regex::new(r#"root_mailbox\s*=\s*"[^"]*""#).unwrap();
+    let example_config = re.replace_all(
+        &example_config,
+        &format!(
+            r#"root_mailbox = "{}""#,
+            std::env::temp_dir().to_str().unwrap()
+        ),
+    );
+
+    let new_file = ConfigFile::new(&example_config).unwrap();
+    let config = FileSettings::validate(new_file.path.clone(), false, true)
+        .expect("Could not parse example config!");
+    for (accname, acc) in config.accounts.iter() {
+        if !acc.extra.is_empty() {
+            panic!(
+                "In example config, account `{}` has unrecognised configuration entries: {:?}",
+                accname, acc.extra
+            );
+        }
+    }
 }