diff --git a/ident_switch-form.js b/ident_switch-form.js
index d5dbf60..4233ad8 100644
--- a/ident_switch-form.js
+++ b/ident_switch-form.js
@@ -46,7 +46,7 @@ $(function() {
 	});
 
 	// IMAP host → update SMTP/Sieve host placeholders
-	$("INPUT[name='_ident_switch.form.imap.host']").on('input change blur', function() {
+	$("INPUT[name='_ident_switch.form.imap.host']").on('change blur', function() {
 		var imapHost = $(this).val() || 'localhost';
 		$("INPUT[name='_ident_switch.form.smtp.host']").attr('placeholder', imapHost);
 		$("INPUT[name='_ident_switch.form.sieve.host']").attr('placeholder', imapHost);
@@ -294,7 +294,7 @@ function plugin_switchIdent_applyJsPreconfig(cfg, email) {
 		var port = cfg[proto].port;
 		var defaultPort = ident_switch_portDefaults[proto][security] || '';
 		$("INPUT[name='_ident_switch.form." + proto + ".port']").val(
-			(port && port != defaultPort) ? port : ''
+			(port && parseInt(port) !== defaultPort) ? port : ''
 		);
 	});
 
diff --git a/ident_switch.php b/ident_switch.php
index 036d333..882e91f 100644
--- a/ident_switch.php
+++ b/ident_switch.php
@@ -33,7 +33,7 @@ class ident_switch extends rcube_plugin
 	/** @var int Flag: account switching is enabled. */
 	public const DB_ENABLED = 1;
 
-	/** @var int Flag: use TLS for IMAP connection. */
+	/** @var int Legacy flag: use TLS for IMAP. Read-only for backward compat; new records store scheme in host. */
 	public const DB_SECURE_IMAP_TLS = 4;
 
 	/** @var int SMTP authentication: use same credentials as IMAP. */
@@ -199,13 +199,7 @@ class ident_switch extends rcube_plugin
 				$accSelected = $r['id'];
 			}
 
-			$lbl = $r['label'];
-			if (!$lbl) {
-				$username = $r['username'] ?: $r['email'];
-				$lbl = str_contains($username, '@')
-					? $username
-					: $username . '@' . ($r['host'] ?: 'localhost');
-			}
+			$lbl = $r['label'] ?: $r['username'] ?: $r['email'];
 			$accNames[] = rcube::Q($lbl);
 		}
 
@@ -464,6 +458,44 @@ class ident_switch extends rcube_plugin
 		return $s !== '' ? $s : null;
 	}
 
+	/**
+	 * Parse scheme prefix (ssl://, tls://) from a host string.
+	 *
+	 * @param string $host Host string, optionally prefixed with ssl:// or tls://.
+	 * @return array{scheme: string, host: string} Parsed scheme and bare host.
+	 */
+	public static function parse_host_scheme(string $host): array
+	{
+		$lower = strtolower($host);
+		if (str_starts_with($lower, 'ssl://')) {
+			return ['scheme' => 'ssl', 'host' => substr($host, 6)];
+		}
+		if (str_starts_with($lower, 'tls://')) {
+			return ['scheme' => 'tls', 'host' => substr($host, 6)];
+		}
+		return ['scheme' => '', 'host' => $host];
+	}
+
+	/**
+	 * Resolve username for an identity: use stored username or fall back to email.
+	 *
+	 * @param int         $iid      Identity ID.
+	 * @param string|null $username Stored username (may be empty).
+	 * @return string Resolved username.
+	 */
+	public static function resolve_username(int $iid, ?string $username): string
+	{
+		if (!empty($username)) {
+			return $username;
+		}
+
+		$rc = rcmail::get_instance();
+		$sql = 'SELECT email FROM ' . $rc->db->table_name('identities') . ' WHERE identity_id = ?';
+		$q = $rc->db->query($sql, $iid);
+		$r = $rc->db->fetch_assoc($q);
+		return $r['email'] ?? '';
+	}
+
 	/**
 	 * Write a message to the plugin's log file.
 	 *
diff --git a/lib/IdentSwitchChecker.php b/lib/IdentSwitchChecker.php
index 1f15dde..0358294 100644
--- a/lib/IdentSwitchChecker.php
+++ b/lib/IdentSwitchChecker.php
@@ -111,20 +111,12 @@ class IdentSwitchChecker
 	{
 		$imap = new rcube_imap_generic();
 
-		$host = $identity['imap_host'] ?: 'localhost';
-		$ssl = null;
+		$parsed = ident_switch::parse_host_scheme($identity['imap_host'] ?: 'localhost');
+		$host = $parsed['host'];
+		$ssl = $parsed['scheme'] ?: null;
 
-		// Parse scheme from host field
-		$hostLower = strtolower($host);
-		if (str_starts_with($hostLower, 'ssl://')) {
-			$ssl = 'ssl';
-			$host = substr($host, 6);
-		} elseif (str_starts_with($hostLower, 'tls://')) {
-			$ssl = 'tls';
-			$host = substr($host, 6);
-		} elseif (!empty($identity['flags']) && ($identity['flags'] & ident_switch::DB_SECURE_IMAP_TLS)) {
-			// Backward compat: old records without scheme in host
-			$ssl = 'tls';
+		if (!$ssl && !empty($identity['flags']) && ($identity['flags'] & ident_switch::DB_SECURE_IMAP_TLS)) {
+			$ssl = 'tls'; // Backward compat: old records without scheme in host
 		}
 
 		$def_port = ($ssl === 'ssl') ? 993 : 143;
diff --git a/lib/IdentSwitchForm.php b/lib/IdentSwitchForm.php
index 1ace377..80a8060 100644
--- a/lib/IdentSwitchForm.php
+++ b/lib/IdentSwitchForm.php
@@ -364,21 +364,11 @@ class IdentSwitchForm
 	}
 
 	/**
-	 * Parse scheme prefix from a host string.
-	 *
-	 * @param string $host Host string, optionally prefixed with ssl:// or tls://.
-	 * @return array{scheme: string, host: string} Parsed scheme and bare host.
+	 * Delegate to ident_switch::parse_host_scheme().
 	 */
 	private static function parse_host_scheme(string $host): array
 	{
-		$lower = strtolower($host);
-		if (str_starts_with($lower, 'ssl://')) {
-			return ['scheme' => 'ssl', 'host' => substr($host, 6)];
-		}
-		if (str_starts_with($lower, 'tls://')) {
-			return ['scheme' => 'tls', 'host' => substr($host, 6)];
-		}
-		return ['scheme' => '', 'host' => $host];
+		return ident_switch::parse_host_scheme($host);
 	}
 
 	/**
diff --git a/lib/IdentSwitchSwitcher.php b/lib/IdentSwitchSwitcher.php
index 387213b..362263e 100644
--- a/lib/IdentSwitchSwitcher.php
+++ b/lib/IdentSwitchSwitcher.php
@@ -66,13 +66,7 @@ class IdentSwitchSwitcher
 			$q = $rc->db->query($sql, $identId, $rc->user->ID);
 			$r = $rc->db->fetch_assoc($q);
 			if (is_array($r)) {
-				if (!$r['username']) {
-					// Load email from identity
-					$sql = 'SELECT email FROM ' . $rc->db->table_name('identities') . ' WHERE identity_id = ?';
-					$q = $rc->db->query($sql, $r['iid']);
-					$rIid = $rc->db->fetch_assoc($q);
-					$r['username'] = $rIid['email'];
-				}
+				$r['username'] = ident_switch::resolve_username((int)$r['iid'], $r['username']);
 
 				ident_switch::write_log("Switching mailbox to one for identity with ID = {$r['iid']} (username = '{$r['username']}').");
 
@@ -95,20 +89,12 @@ class IdentSwitchSwitcher
 					}
 				}
 
-				$host = $r['imap_host'] ?: 'localhost';
-				$ssl = null;
+				$parsed = ident_switch::parse_host_scheme($r['imap_host'] ?: 'localhost');
+				$host = $parsed['host'];
+				$ssl = $parsed['scheme'] ?: null;
 
-				// Parse scheme from host field
-				$hostLower = strtolower($host);
-				if (str_starts_with($hostLower, 'ssl://')) {
-					$ssl = 'ssl';
-					$host = substr($host, 6);
-				} elseif (str_starts_with($hostLower, 'tls://')) {
-					$ssl = 'tls';
-					$host = substr($host, 6);
-				} elseif ($r['flags'] & ident_switch::DB_SECURE_IMAP_TLS) {
-					// Backward compat: old records without scheme in host
-					$ssl = 'tls';
+				if (!$ssl && ($r['flags'] & ident_switch::DB_SECURE_IMAP_TLS)) {
+					$ssl = 'tls'; // Backward compat: old records without scheme in host
 				}
 
 				$def_port = ($ssl === 'ssl') ? 993 : 143;
@@ -188,13 +174,7 @@ class IdentSwitchSwitcher
 				$iid = $r['iid'];
 			}
 
-			if (!$r['username']) {
-				// Load email from identity
-				$sql = 'SELECT email FROM ' . $rc->db->table_name('identities') . ' WHERE identity_id = ?';
-				$q = $rc->db->query($sql, $iid);
-				$rIid = $rc->db->fetch_assoc($q);
-				$r['username'] = $rIid['email'];
-			}
+			$r['username'] = ident_switch::resolve_username($iid, $r['username']);
 
 			$authMode = (int)$r['smtp_auth'];
 			if ($authMode === ident_switch::SMTP_AUTH_CUSTOM) {
@@ -264,12 +244,7 @@ class IdentSwitchSwitcher
 				return $args;
 			}
 
-			if (!$r['username']) {
-				$sql = 'SELECT email FROM ' . $rc->db->table_name('identities') . ' WHERE identity_id = ?';
-				$q = $rc->db->query($sql, $iid);
-				$rIid = $rc->db->fetch_assoc($q);
-				$r['username'] = $rIid['email'];
-			}
+			$r['username'] = ident_switch::resolve_username($iid, $r['username']);
 
 			$sieveHost = $r['sieve_host'];
 			$sievePort = $r['sieve_port'] ?: 4190;