diff --git a/src/account-manager/controller/account.go b/src/account-manager/controller/account.go
new file mode 100644
index 0000000..b631521
--- /dev/null
+++ b/src/account-manager/controller/account.go
@@ -0,0 +1,197 @@
+package controller
+
+import (
+	"errors"
+	"fmt"
+	"io"
+	"os"
+	"os/exec"
+	"path"
+	"strings"
+
+	"jupiter-mail.org/account-manager/model"
+)
+
+var USERDB_PATH = path.Clean("/etc/dovecot/userdb")
+const ROOT_UID = 0
+const DOVECOT_GID = 106
+
+func OpenUserDB() (*os.File, error) {
+	err := os.MkdirAll(path.Dir(USERDB_PATH), 0755)
+	if err != nil { return nil, err }
+
+	file, err := os.OpenFile(USERDB_PATH, os.O_CREATE | os.O_RDWR, 0640)
+	if err != nil && errors.Is(err, os.ErrExist) { return nil, err }
+
+	if err := file.Chown(ROOT_UID, DOVECOT_GID); err != nil { return nil, err }
+
+	return file, nil
+}
+
+func FetchAccount(username string, domain string) (*model.MailAccount, error) {
+	accounts, err := FetchAccounts()
+	if err != nil {
+		return nil, fmt.Errorf("fetch accounts: %v", err)
+	}
+
+	for _, account := range accounts {
+		if account.Username == username && account.Domain == domain {
+			return account, nil
+		}
+	}
+
+	return nil, fmt.Errorf("account does not exist: %s@%s", username, domain)
+}
+
+func IfAccountExists(username string, domain string) (bool, error) {
+	accounts, err := FetchAccounts()
+	if err != nil {
+		return false, fmt.Errorf("fetch accounts: %v", err)
+	}
+
+	for _, account := range accounts {
+		if account.Username == username && account.Domain == domain {
+			return true, nil
+		}
+	}
+
+	return false, nil
+}
+
+func HashPassword(username string, domain string, password string) ([]byte, error) {
+	// doveadm pw -s SHA512-CRYPT -u "$USERNAME" -p "$PASSWORD"
+	hashCmd := exec.Command(
+		"doveadm", "pw",
+		"-s", "SHA512-CRYPT",
+		"-u", fmt.Sprintf("%s@%s", username, domain),
+		"-p", password,
+	)
+	out, err := hashCmd.Output()
+	if err != nil { return nil, err }
+	return out, nil
+}
+
+func WriteAccounts(accounts []*model.MailAccount) (error) {
+	newUserDb := strings.Builder{}
+	for _, account := range accounts {
+		newUserDb.WriteString(account.UserDbLine())
+	}
+
+	if err := os.WriteFile(USERDB_PATH, []byte(newUserDb.String()), 0640); err != nil {
+		return fmt.Errorf("write userdb: %v", err)
+	}
+
+	return nil
+}
+
+func CreateAccount(username string, domain string, password string) (*model.MailAccount, error) {
+	exists, err := IfAccountExists(username, domain)
+	if err != nil { return nil, fmt.Errorf("failed to check if account exists: %v", err)  }
+	if exists { return nil, fmt.Errorf("account already exists: %s@%s", username, domain) }
+
+	passwordHash, err := HashPassword(username, domain, password)
+	if err != nil { return nil, fmt.Errorf("hash password: %v", err) }
+
+	account := &model.MailAccount{
+		Username: username,
+		Domain: domain,
+		PasswordHash: []byte(passwordHash),
+	}
+	account.MailDirectory = account.DefaultMailHome()
+
+	accounts, err := FetchAccounts()
+	if err != nil { return nil, fmt.Errorf("failed to fetch accounts: %v", err) }
+	accounts = append(accounts, account)
+
+	if err = WriteAccounts(accounts); err != nil {
+		return nil, fmt.Errorf("write accounts: %v", err)
+	}
+
+	return account, nil
+}
+
+func FetchAccounts() ([]*model.MailAccount, error) {
+	file, err := OpenUserDB()
+	if err != nil { return nil, fmt.Errorf("open userdb: %v", err)  }
+	defer file.Close()
+
+	data, err := io.ReadAll(file)
+	if err != nil { return nil, fmt.Errorf("read userdb: %v", err)  }
+
+	lines := strings.Split(string(data), "\n")
+	accounts := []*model.MailAccount{}
+	for i, line := range lines {
+		if len(line) == 0 { continue }
+		segments := strings.Split(line, ":")
+		if len(segments) != 8 {
+			return nil, fmt.Errorf("malformed data on line %d", i)
+		}
+
+		// <username>:<password>:5000:5000::/var/mail/<domain>/<user>/home::
+		fullUsername := segments[0]
+		usernameSplits := strings.Split(fullUsername, "@")
+		if len(usernameSplits) != 2 {
+			return nil, fmt.Errorf("invalid email format on line %d: %s", i, fullUsername)
+		}
+		username := usernameSplits[0]
+		domain := usernameSplits[1]
+
+		passwordHash := []byte(segments[1])
+		mailDir := segments[5]
+		account := &model.MailAccount{
+			Username: username,
+			Domain: domain,
+			PasswordHash: passwordHash,
+			MailDirectory: mailDir,
+		}
+		account.MailDirectory = mailDir
+		accounts = append(accounts, account)
+	}
+
+	return accounts, nil
+}
+
+func UpdateAccount(username string, domain string, password string) (error) {
+	accounts, err := FetchAccounts()
+	if err != nil { return fmt.Errorf("fetch accounts: %v", err) }
+
+	var account *model.MailAccount = nil
+	for _, acc := range accounts {
+		if acc.Username == username && acc.Domain == domain {
+			account = acc
+			break
+		}
+	}
+	if account == nil { return fmt.Errorf("account does not exist: %s@%s", username, domain) }
+
+	passwordHash, err := HashPassword(username, domain, password)
+	if err != nil { return fmt.Errorf("hash password: %v", err) }
+	account.PasswordHash = passwordHash
+
+	WriteAccounts(accounts)
+
+	return nil
+}
+
+func DeleteAccount(username string, domain string) (error) {
+	accounts, err := FetchAccounts()
+	if err != nil { return fmt.Errorf("fetch accounts: %v", err) }
+
+	userDbFile, err := OpenUserDB()
+	if err != nil { return fmt.Errorf("open userdb: %v", err) }
+	defer userDbFile.Close()
+
+	newAccounts := []*model.MailAccount{}
+	for _, account := range accounts {
+		if account.Username != username || account.Domain != domain {
+			newAccounts = append(newAccounts, account)
+		}
+	}
+
+	if err := WriteAccounts(newAccounts); err != nil {
+		return fmt.Errorf("write accounts: %v", err)
+	}
+
+	return nil
+}
+
diff --git a/src/account-manager/main.go b/src/account-manager/main.go
index fcd3c5c..a4aecb5 100644
--- a/src/account-manager/main.go
+++ b/src/account-manager/main.go
@@ -2,23 +2,17 @@ package main
 
 import (
 	_ "embed"
-	"errors"
 	"fmt"
-	"io"
 	"log"
 	"os"
-	"os/exec"
-	"path"
 	"strings"
 
-	"jupiter-mail.org/account-manager/model"
+	"jupiter-mail.org/account-manager/controller"
 )
 
 //go:embed res/help.txt
 var helpText string
 
-var USERDB_PATH = path.Clean("/etc/dovecot/userdb")
-
 func main() {
 	if len(os.Args) < 2 {
 		fmt.Fprintln(os.Stderr, helpText)
@@ -27,110 +21,74 @@ func main() {
 
 	switch os.Args[1] {
 	case "create":
-		account, err := createAccount(os.Args[2], os.Args[3])
+		if len(os.Args) < 3 {
+			log.Fatalf("usage: accounts create <username> <password>")
+			os.Exit(1)
+		}
+		usernameSplits := strings.Split(os.Args[2], "@")
+		if len(usernameSplits) != 2 {
+			log.Fatalf("Invalid email format: %s", os.Args[2])
+			os.Exit(1)
+		}
+		username := usernameSplits[0]
+		domain := usernameSplits[1]
+		account, err := controller.CreateAccount(username, domain, os.Args[3])
 		if err != nil {
 			log.Fatalf("Failed to create account: %v", err)
 			os.Exit(1)
 		}
 		log.Printf("Account \"%s\" created successfully.", account.FullUsername())
 	case "list":
-		log.Fatalf("list: not implemented")
-		os.Exit(1)
+		accounts, err := controller.FetchAccounts()
+		if err != nil {
+			log.Fatalf("Failed to fetch accounts: %v", err)
+			os.Exit(1)
+		}
+		for _, account := range accounts {
+			fmt.Printf(
+				"%s:\n\thome: %s\n",
+				account.FullUsername(),
+				account.MailDirectory,
+			)
+		}
 	case "update":
-		log.Fatalf("update: not implemented")
-		os.Exit(1)
+		if len(os.Args) < 3 {
+			log.Fatalf("usage: accounts update <username> <password>")
+			os.Exit(1)
+		}
+		usernameSplits := strings.Split(os.Args[2], "@")
+		if len(usernameSplits) != 2 {
+			log.Fatalf("Invalid email format: %s", os.Args[2])
+			os.Exit(1)
+		}
+		username := usernameSplits[0]
+		domain := usernameSplits[1]
+		err := controller.UpdateAccount(username, domain, os.Args[3])
+		if err != nil {
+			log.Fatalf("Failed to update account: %s", os.Args[2])
+			os.Exit(1)
+		}
+		log.Printf("%s password updated successfully.", os.Args[2])
 	case "delete":
-		log.Fatalf("delete: not implemented")
-		os.Exit(1)
+		if len(os.Args) < 2 {
+			log.Fatalf("usage: accounts delete <username>")
+			os.Exit(1)
+		}
+		usernameSplits := strings.Split(os.Args[2], "@")
+		if len(usernameSplits) != 2 {
+			log.Fatalf("Invalid email format: %s", os.Args[2])
+			os.Exit(1)
+		}
+		username := usernameSplits[0]
+		domain := usernameSplits[1]
+		err := controller.DeleteAccount(username, domain)
+		if err != nil {
+			log.Fatalf("Failed to delete account: %s", os.Args[2])
+			os.Exit(1)
+		}
+		log.Printf("%s deleted successfully.", os.Args[2])
 	default:
 		log.Fatalf("Unrecognised action \"%s\"", os.Args[1])
 		os.Exit(1)
 	}
 }
-
-func openUserDB() (*os.File, error) {
-	err := os.MkdirAll(path.Dir(USERDB_PATH), 0755)
-	if err != nil { return nil, err }
-
-	file, err := os.OpenFile(USERDB_PATH, os.O_CREATE | os.O_RDWR, 0640)
-	if err != nil && errors.Is(err, os.ErrExist) { return nil, err }
-
-	return file, nil
-}
-
-func getMailHome(user string, domain string) string {
-	return fmt.Sprintf("/var/mail/%s/%s/home", domain, user)
-}
-
-func checkAccountExists(username string) (bool, error) {
-	file, err := openUserDB()
-	if err != nil { return false, fmt.Errorf("open userdb: %v", err)  }
-
-	data, err := io.ReadAll(file)
-	if err != nil { return false, fmt.Errorf("read userdb: %v", err)  }
-	file.Close()
-
-	lines := strings.Split(string(data), "\n")
-	for _, line := range lines {
-		if strings.HasPrefix(line, username) { return true, nil }
-	}
-
-	return false, nil
-}
-
-func createAccount(fullUsername string, password string) (*model.MailAccount, error) {
-	exists, err := checkAccountExists(fullUsername)
-	if err != nil { return nil, fmt.Errorf("failed to check if account exists: %v", err)  }
-	if exists { return nil, fmt.Errorf("account already exists: %s", fullUsername) }
-
-	usernameSplits := strings.Split(fullUsername, "@")
-	if len(usernameSplits) != 2 {
-		return nil, fmt.Errorf("invalid email format: %s", fullUsername)
-	}
-	username := usernameSplits[0]
-	domain := usernameSplits[1]
-
-	passwordHash, err := hashPassword(username, password)
-	if err != nil { return nil, fmt.Errorf("hash password: %v", err) }
-
-	account := model.NewMailAccount(username, domain, []byte(passwordHash))
-
-	uid := 5000; gid := 5000
-	// <username>:<password>:5000:5000::/var/mail/<domain>/<user>/home::
-	userDbLine := fmt.Sprintf(
-		"%s:%s:%d:%d::%s::\n",
-		account.FullUsername(),
-		account.PasswordHash,
-		uid, gid,
-		getMailHome(account.Username, account.Domain),
-	)
-
-	file, err := openUserDB()
-	if err != nil { return nil, fmt.Errorf("open userdb: %v", err) }
-	buf := make([]byte, 1024)
-	for n, err := file.Read(buf); n > 0; {
-		if err != nil {
-			return nil, fmt.Errorf("read userdb: %v", err)
-		}
-	}
-	_, err = file.Write([]byte(userDbLine))
-	if err != nil { return nil, err }
-
-	err = file.Close()
-	if err != nil { return nil, err }
-
-	return &account, nil
-}
-
-func hashPassword(username string, password string) (string, error) {
-	// doveadm pw -s SHA512-CRYPT -u "$USERNAME" -p "$PASSWORD"
-	hashCmd := exec.Command(
-		"doveadm", "pw",
-		"-s", "SHA512-CRYPT",
-		"-u", username,
-		"-p", password,
-	)
-	out, err := hashCmd.Output()
-	if err != nil { return "", err }
-	return string(out), nil
-}
diff --git a/src/account-manager/model/account.go b/src/account-manager/model/account.go
index c7a68d3..2cc3742 100644
--- a/src/account-manager/model/account.go
+++ b/src/account-manager/model/account.go
@@ -1,23 +1,39 @@
 package model
 
-import "fmt"
+import (
+	"fmt"
+	"strings"
+)
 
 type (
 	MailAccount struct {
 		Username		string `json:"username"`
 		Domain			string `json:"domain"`
 		PasswordHash	[]byte `json:"password"`
+		MailDirectory	string `json:"mail_dir"`
 	}
 )
 
-func NewMailAccount(username string, domain string, passwordHash []byte) MailAccount {
-	return MailAccount{
-		Username: username,
-		Domain: domain,
-		PasswordHash: passwordHash,
-	}
-}
-
 func (account *MailAccount) FullUsername() string {
 	return fmt.Sprintf("%s@%s", account.Username, account.Domain)
 }
+
+func (account *MailAccount) UserDbLine() string {
+	uid := 5000; gid := 5000
+	// <username>:<password>:5000:5000::/var/mail/<domain>/<user>/home::
+	return fmt.Sprintf(
+		"%s:%s:%d:%d::%s::\n",
+		account.FullUsername(),
+		strings.Trim(string(account.PasswordHash), " \n"),
+		uid, gid,
+		account.DefaultMailHome(),
+	)
+}
+
+func (account *MailAccount) DefaultMailHome() string {
+	return fmt.Sprintf(
+		"/var/mail/%s/%s/home",
+		account.Domain,
+		account.Username,
+	)
+}
diff --git a/target/scripts/start-services.sh b/target/scripts/start-services.sh
index 2ccf1b9..54416b8 100644
--- a/target/scripts/start-services.sh
+++ b/target/scripts/start-services.sh
@@ -23,6 +23,6 @@ log "info" "Starting daemons..."
 start_daemon saslauthd
 start_daemon postgresql
 start_daemon dovecot
-start_daemon postfix
+# start_daemon postfix
 
 exec tail "${LOGFILE}"