diff --git a/lib/Client/Protocol/Command/AppendCommand.php b/lib/Client/Protocol/Command/AppendCommand.php
index e50d1c4..e296472 100644
--- a/lib/Client/Protocol/Command/AppendCommand.php
+++ b/lib/Client/Protocol/Command/AppendCommand.php
@@ -4,6 +4,7 @@ declare(strict_types=1);
 
 namespace KTXM\ProviderImap\Client\Protocol\Command;
 
+use KTXM\ProviderImap\Client\Protocol\StringEncoder;
 use KTXM\ProviderImap\Client\ImapException;
 use KTXM\ProviderImap\Client\Protocol\RequestFrame;
 use KTXM\ProviderImap\Client\Protocol\Response\ContinuationResponse;
@@ -57,7 +58,7 @@ final class AppendCommand implements CommandInterface
 
         return new RequestFrame(sprintf(
             'APPEND %s %s{%d}',
-            $this->quote($this->mailbox),
+            StringEncoder::quote($this->mailbox),
             $flagSegment,
             strlen($this->literal),
         ));
@@ -86,10 +87,6 @@ final class AppendCommand implements CommandInterface
         throw new ImapException('APPEND did not receive a tagged completion response.');
     }
 
-    private function quote(string $mailbox): string
-    {
-        return '"' . addcslashes($mailbox, "\\\"") . '"';
-    }
 
     private function parseAppendUid(string $text): ?int
     {
diff --git a/lib/Client/Protocol/Command/Argument/SearchCriteriaBuilder.php b/lib/Client/Protocol/Command/Argument/SearchCriteriaBuilder.php
index 705e204..02fd558 100644
--- a/lib/Client/Protocol/Command/Argument/SearchCriteriaBuilder.php
+++ b/lib/Client/Protocol/Command/Argument/SearchCriteriaBuilder.php
@@ -4,6 +4,7 @@ declare(strict_types=1);
 
 namespace KTXM\ProviderImap\Client\Protocol\Command\Argument;
 
+use KTXM\ProviderImap\Client\Protocol\StringEncoder;
 use KTXM\ProviderImap\Client\Protocol\SequenceSet;
 
 use DateTimeInterface;
@@ -190,8 +191,8 @@ final class SearchCriteriaBuilder
     {
         return $this->pushExpression(sprintf(
             'HEADER %s %s',
-            $this->formatString($name),
-            $this->formatString($value),
+            StringEncoder::quote($name),
+            StringEncoder::quote($value),
         ));
     }
 
@@ -287,7 +288,7 @@ final class SearchCriteriaBuilder
         return $this->pushExpression(sprintf(
             '%s %s',
             $key,
-            $quote ? $this->formatString($value) : $value,
+            $quote ? StringEncoder::quote($value) : $value,
         ));
     }
 
@@ -371,9 +372,4 @@ final class SearchCriteriaBuilder
             default => SequenceSet::parse($value)->toCommand(),
         };
     }
-
-    private function formatString(string $value): string
-    {
-        return '"' . addcslashes($value, "\\\"") . '"';
-    }
 }
\ No newline at end of file
diff --git a/lib/Client/Protocol/Command/CreateCommand.php b/lib/Client/Protocol/Command/CreateCommand.php
index c64c2ca..b95928a 100644
--- a/lib/Client/Protocol/Command/CreateCommand.php
+++ b/lib/Client/Protocol/Command/CreateCommand.php
@@ -4,6 +4,7 @@ declare(strict_types=1);
 
 namespace KTXM\ProviderImap\Client\Protocol\Command;
 
+use KTXM\ProviderImap\Client\Protocol\StringEncoder;
 use KTXM\ProviderImap\Client\Result\CommandStatusResult;
 use KTXM\ProviderImap\Client\ImapException;
 use KTXM\ProviderImap\Client\Protocol\RequestFrame;
@@ -38,7 +39,7 @@ final class CreateCommand implements CommandInterface
     {
         unset($tag, $context);
 
-        return new RequestFrame(sprintf('CREATE %s', $this->quote($this->mailbox)));
+        return new RequestFrame(sprintf('CREATE %s', StringEncoder::quote($this->mailbox)));
     }
 
     public function handle(ResponseStream $responses, SessionContext $context): CommandStatusResult
@@ -57,9 +58,4 @@ final class CreateCommand implements CommandInterface
 
         throw new ImapException('CREATE did not receive a tagged completion response.');
     }
-
-    private function quote(string $value): string
-    {
-        return '"' . addcslashes($value, "\\\"") . '"';
-    }
 }
\ No newline at end of file
diff --git a/lib/Client/Protocol/Command/DeleteCommand.php b/lib/Client/Protocol/Command/DeleteCommand.php
index 6f104df..f2c22d8 100644
--- a/lib/Client/Protocol/Command/DeleteCommand.php
+++ b/lib/Client/Protocol/Command/DeleteCommand.php
@@ -4,6 +4,7 @@ declare(strict_types=1);
 
 namespace KTXM\ProviderImap\Client\Protocol\Command;
 
+use KTXM\ProviderImap\Client\Protocol\StringEncoder;
 use KTXM\ProviderImap\Client\Result\CommandStatusResult;
 use KTXM\ProviderImap\Client\ImapException;
 use KTXM\ProviderImap\Client\Protocol\RequestFrame;
@@ -38,7 +39,7 @@ final class DeleteCommand implements CommandInterface
     {
         unset($tag, $context);
 
-        return new RequestFrame(sprintf('DELETE %s', $this->quote($this->mailbox)));
+        return new RequestFrame(sprintf('DELETE %s', StringEncoder::quote($this->mailbox)));
     }
 
     public function handle(ResponseStream $responses, SessionContext $context): CommandStatusResult
@@ -60,9 +61,4 @@ final class DeleteCommand implements CommandInterface
 
         throw new ImapException('DELETE did not receive a tagged completion response.');
     }
-
-    private function quote(string $value): string
-    {
-        return '"' . addcslashes($value, "\\\"") . '"';
-    }
 }
\ No newline at end of file
diff --git a/lib/Client/Protocol/Command/ListCommand.php b/lib/Client/Protocol/Command/ListCommand.php
index 1be8801..e223af5 100644
--- a/lib/Client/Protocol/Command/ListCommand.php
+++ b/lib/Client/Protocol/Command/ListCommand.php
@@ -4,6 +4,7 @@ declare(strict_types=1);
 
 namespace KTXM\ProviderImap\Client\Protocol\Command;
 
+use KTXM\ProviderImap\Client\Protocol\StringEncoder;
 use KTXM\ProviderImap\Client\Protocol\Parser\ListResponseParser;
 use KTXM\ProviderImap\Client\Protocol\Parser\StatusResponseParser;
 use Generator;
@@ -66,8 +67,8 @@ final class ListCommand implements CommandInterface
 
         $command .= sprintf(
             ' %s %s',
-            $this->quote($this->reference),
-            $this->quote($this->pattern),
+            StringEncoder::quote($this->reference),
+            StringEncoder::quote($this->pattern),
         );
 
         $returnOptions = $this->returnOptions->toCommand();
@@ -158,9 +159,4 @@ final class ListCommand implements CommandInterface
             $mailbox->readOnly(),
         );
     }
-
-    private function quote(string $value): string
-    {
-        return '"' . addcslashes($value, "\\\"") . '"';
-    }
 }
\ No newline at end of file
diff --git a/lib/Client/Protocol/Command/LoginCommand.php b/lib/Client/Protocol/Command/LoginCommand.php
index 14aa885..c932a0e 100644
--- a/lib/Client/Protocol/Command/LoginCommand.php
+++ b/lib/Client/Protocol/Command/LoginCommand.php
@@ -4,6 +4,7 @@ declare(strict_types=1);
 
 namespace KTXM\ProviderImap\Client\Protocol\Command;
 
+use KTXM\ProviderImap\Client\Protocol\StringEncoder;
 use KTXM\ProviderImap\Client\Result\CommandStatusResult;
 use KTXM\ProviderImap\Client\ImapException;
 use KTXM\ProviderImap\Client\Protocol\RequestFrame;
@@ -38,8 +39,8 @@ final class LoginCommand implements CommandInterface
 
         return new RequestFrame(sprintf(
             'LOGIN %s %s',
-            $this->quote($this->username),
-            $this->quote($this->password),
+            StringEncoder::quote($this->username),
+            StringEncoder::quote($this->password),
         ));
     }
 
@@ -59,9 +60,4 @@ final class LoginCommand implements CommandInterface
 
         throw new ImapException('LOGIN did not receive a tagged completion response.');
     }
-
-    private function quote(string $value): string
-    {
-        return '"' . addcslashes($value, "\\\"") . '"';
-    }
 }
\ No newline at end of file
diff --git a/lib/Client/Protocol/Command/MessageTransferCommand.php b/lib/Client/Protocol/Command/MessageTransferCommand.php
index 9e9e658..ae4f550 100644
--- a/lib/Client/Protocol/Command/MessageTransferCommand.php
+++ b/lib/Client/Protocol/Command/MessageTransferCommand.php
@@ -4,6 +4,7 @@ declare(strict_types=1);
 
 namespace KTXM\ProviderImap\Client\Protocol\Command;
 
+use KTXM\ProviderImap\Client\Protocol\StringEncoder;
 use KTXM\ProviderImap\Client\Result\MessageTransferResult;
 use KTXM\ProviderImap\Client\Protocol\Command\Argument\MessageTarget;
 use KTXM\ProviderImap\Client\Protocol\IdentifierMode;
@@ -66,7 +67,7 @@ final class MessageTransferCommand implements CommandInterface
             $this->identifierMode === IdentifierMode::Uid ? 'UID ' : '',
             $this->operation,
             $this->sequenceSet->toCommand(),
-            $this->quote($this->destinationMailbox),
+            StringEncoder::quote($this->destinationMailbox),
         ));
     }
 
@@ -235,9 +236,4 @@ final class MessageTransferCommand implements CommandInterface
             'text' => trim($matches[3] ?? ''),
         ];
     }
-
-    private function quote(string $value): string
-    {
-        return '"' . addcslashes($value, "\\\"") . '"';
-    }
 }
\ No newline at end of file
diff --git a/lib/Client/Protocol/Command/RenameCommand.php b/lib/Client/Protocol/Command/RenameCommand.php
index e04b1a4..5a2118c 100644
--- a/lib/Client/Protocol/Command/RenameCommand.php
+++ b/lib/Client/Protocol/Command/RenameCommand.php
@@ -4,6 +4,7 @@ declare(strict_types=1);
 
 namespace KTXM\ProviderImap\Client\Protocol\Command;
 
+use KTXM\ProviderImap\Client\Protocol\StringEncoder;
 use KTXM\ProviderImap\Client\Result\CommandStatusResult;
 use KTXM\ProviderImap\Client\ImapException;
 use KTXM\ProviderImap\Client\Protocol\RequestFrame;
@@ -41,8 +42,8 @@ final class RenameCommand implements CommandInterface
 
         return new RequestFrame(sprintf(
             'RENAME %s %s',
-            $this->quote($this->fromMailbox),
-            $this->quote($this->toMailbox),
+            StringEncoder::quote($this->fromMailbox),
+            StringEncoder::quote($this->toMailbox),
         ));
     }
 
@@ -64,9 +65,4 @@ final class RenameCommand implements CommandInterface
 
         throw new ImapException('RENAME did not receive a tagged completion response.');
     }
-
-    private function quote(string $value): string
-    {
-        return '"' . addcslashes($value, "\\\"") . '"';
-    }
 }
\ No newline at end of file
diff --git a/lib/Client/Protocol/Command/SelectCommand.php b/lib/Client/Protocol/Command/SelectCommand.php
index a3dc846..13f014d 100644
--- a/lib/Client/Protocol/Command/SelectCommand.php
+++ b/lib/Client/Protocol/Command/SelectCommand.php
@@ -4,6 +4,7 @@ declare(strict_types=1);
 
 namespace KTXM\ProviderImap\Client\Protocol\Command;
 
+use KTXM\ProviderImap\Client\Protocol\StringEncoder;
 use KTXM\ProviderImap\Client\ImapException;
 use KTXM\ProviderImap\Client\Mailbox;
 use KTXM\ProviderImap\Client\Protocol\RequestFrame;
@@ -43,7 +44,7 @@ final class SelectCommand implements CommandInterface
         return new RequestFrame(sprintf(
             '%s %s',
             $this->name(),
-            $this->quote($this->mailbox),
+            StringEncoder::quote($this->mailbox),
         ));
     }
 
@@ -116,9 +117,4 @@ final class SelectCommand implements CommandInterface
 
         return preg_split('/\s+/', $flags) ?: [];
     }
-
-    private function quote(string $value): string
-    {
-        return '"' . addcslashes($value, "\\\"") . '"';
-    }
 }
\ No newline at end of file
diff --git a/lib/Client/Protocol/Command/StatusCommand.php b/lib/Client/Protocol/Command/StatusCommand.php
index 68470f8..89bb0ef 100644
--- a/lib/Client/Protocol/Command/StatusCommand.php
+++ b/lib/Client/Protocol/Command/StatusCommand.php
@@ -4,6 +4,7 @@ declare(strict_types=1);
 
 namespace KTXM\ProviderImap\Client\Protocol\Command;
 
+use KTXM\ProviderImap\Client\Protocol\StringEncoder;
 use KTXM\ProviderImap\Client\Protocol\Parser\StatusResponseParser;
 use KTXM\ProviderImap\Client\Result\StatusResult;
 use KTXM\ProviderImap\Client\ImapException;
@@ -51,7 +52,7 @@ final class StatusCommand implements CommandInterface
 
         return new RequestFrame(sprintf(
             'STATUS %s (%s)',
-            $this->quote($this->mailbox),
+            StringEncoder::quote($this->mailbox),
             implode(' ', $this->normalizeItems($this->items)),
         ));
     }
@@ -112,8 +113,4 @@ final class StatusCommand implements CommandInterface
 
         return $normalized;
     }
-    private function quote(string $value): string
-    {
-        return '"' . addcslashes($value, "\\\"") . '"';
-    }
 }
\ No newline at end of file
diff --git a/lib/Client/Protocol/StringEncoder.php b/lib/Client/Protocol/StringEncoder.php
new file mode 100644
index 0000000..1e30003
--- /dev/null
+++ b/lib/Client/Protocol/StringEncoder.php
@@ -0,0 +1,13 @@
+<?php
+
+declare(strict_types=1);
+
+namespace KTXM\ProviderImap\Client\Protocol;
+
+final class StringEncoder
+{
+    public static function quote(string $value): string
+    {
+        return '"' . addcslashes($value, "\\\"") . '"';
+    }
+}