diff --git a/app/Livewire/Mailbox.php b/app/Livewire/Mailbox.php
index 82fff52..212cd0d 100644
--- a/app/Livewire/Mailbox.php
+++ b/app/Livewire/Mailbox.php
@@ -223,7 +223,7 @@ class Mailbox extends Component
             'created_ip' => request()->ip(),
             'last_accessed_ip' => request()->ip(),
             'last_accessed_at' => now(),
-            'expires_at' => now()->addDays(7), // Default expiry
+            'expires_at' => now()->addDays($this->getValidityDays()),
         ]);
 
         $this->currentMailboxId = $mailbox->id;
@@ -262,7 +262,7 @@ class Mailbox extends Component
             'created_ip' => request()->ip(),
             'last_accessed_ip' => request()->ip(),
             'last_accessed_at' => now(),
-            'expires_at' => now()->addDays(7),
+            'expires_at' => now()->addDays($this->getValidityDays()),
         ]);
 
         $this->currentMailboxId = $mailbox->id;
@@ -270,6 +270,27 @@ class Mailbox extends Component
         Session::put('current_mailbox_id', $mailbox->id);
     }
 
+    /**
+     * Get mailbox lifespan in days based on user tier.
+     * Guest: 1 day, Free: 3 days, Pro: 7 days, Enterprise: 14 days.
+     */
+    protected function getValidityDays(): int
+    {
+        $user = auth()->user();
+
+        if (! $user) {
+            return 1; // Guests get 24 hours
+        }
+
+        return match (true) {
+            $user->isEnterprise() => 14,
+            $user->isAdmin() => 14, // Assuming admins get enterprise limits
+            $user->isPro() => 7,
+            $user->isFree() => 3,
+            default => 3,
+        };
+    }
+
     public function finishAutoCreation(): void
     {
         if ($this->getActiveMailboxesProperty()->isEmpty()) {
diff --git a/resources/views/livewire/mailbox.blade.php b/resources/views/livewire/mailbox.blade.php
index 0057257..2a06150 100644
--- a/resources/views/livewire/mailbox.blade.php
+++ b/resources/views/livewire/mailbox.blade.php
@@ -154,18 +154,58 @@
                             </div>
                         </div>
                         <div class="text-[11px] font-mono text-white break-all mb-4">{{ $currentMailbox->address }}</div>
-                        <div class="space-y-2">
+                        <div class="space-y-2" 
+                             x-data="{
+                                expiresAt: '{{ $currentMailbox->expires_at?->toIso8601String() }}',
+                                created_at: '{{ $currentMailbox->created_at?->toIso8601String() }}',
+                                timeLeft: 'Never',
+                                percent: 100,
+                                init() {
+                                    if (!this.expiresAt) return;
+                                    
+                                    this.update();
+                                    setInterval(() => this.update(), 1000);
+                                },
+                                update() {
+                                    const end = new Date(this.expiresAt).getTime();
+                                    const start = new Date(this.created_at).getTime();
+                                    const now = new Date().getTime();
+                                    
+                                    if (now > end) {
+                                        this.timeLeft = 'Expired';
+                                        this.percent = 0;
+                                        return;
+                                    }
+                                    
+                                    // Calculate time string
+                                    const diff = end - now;
+                                    const days = Math.floor(diff / (1000 * 60 * 60 * 24));
+                                    const hours = Math.floor((diff % (1000 * 60 * 60 * 24)) / (1000 * 60 * 60));
+                                    const mins = Math.floor((diff % (1000 * 60 * 60)) / (1000 * 60));
+                                    const secs = Math.floor((diff % (1000 * 60)) / 1000);
+                                    
+                                    if (days > 0) {
+                                        this.timeLeft = `${days}d ${hours}h ${mins}m ${secs}s`;
+                                    } else if (hours > 0) {
+                                        this.timeLeft = `${hours}h ${mins}m ${secs}s`;
+                                    } else if (mins > 0) {
+                                        this.timeLeft = `${mins}m ${secs}s`;
+                                    } else {
+                                        this.timeLeft = `${secs}s`;
+                                    }
+                                    
+                                    // Calculate percentage based on total lifespan vs remaining
+                                    const totalLifespan = end - start;
+                                    const timeRemaining = end - now;
+                                    this.percent = Math.max(0, Math.min(100, (timeRemaining / totalLifespan) * 100));
+                                }
+                             }">
                             <div class="flex items-center justify-between text-[10px]">
                                 <span class="text-zinc-500 uppercase font-black tracking-tighter">Expires In</span>
-                                <span class="text-pink-500 font-mono">{{ $currentMailbox->expires_at?->diffForHumans(['parts' => 2, 'short' => true]) ?? 'Never' }}</span>
+                                <span class="text-pink-500 font-mono" x-text="timeLeft"></span>
                             </div>
                             <div class="h-1 bg-white/5 rounded-full overflow-hidden">
-                                @php
-                                    $percent = $currentMailbox->expires_at 
-                                        ? max(0, min(100, (now()->diffInSeconds($currentMailbox->expires_at) / (86400 * 7)) * 100))
-                                        : 100;
-                                @endphp
-                                <div class="h-full bg-gradient-to-r from-pink-500 to-emerald-500" style="width: {{ $percent }}%"></div>
+                                <div class="h-full bg-gradient-to-r from-pink-500 to-emerald-500 transition-all duration-1000 ease-linear" :style="`width: ${percent}%`"></div>
                             </div>
                         </div>
                     </div>
@@ -191,9 +231,43 @@
                                     @if($mailbox->id !== $currentMailboxId)
                                         <button wire:click="switchMailbox({{ $mailbox->id }})" 
                                                 class="w-full p-3 rounded-xl bg-zinc-900/40 border border-white/5 text-left group hover:border-white/20 transition-all flex items-center justify-between cursor-pointer">
-                                            <div class="min-w-0 flex-1">
+                                            <div class="min-w-0 flex-1"
+                                                 x-data="{
+                                                    expiresAt: '{{ $mailbox->expires_at?->toIso8601String() }}',
+                                                    timeLeft: 'Never',
+                                                    init() {
+                                                        if (!this.expiresAt) return;
+                                                        this.update();
+                                                        setInterval(() => this.update(), 1000); // 1-sec interval
+                                                    },
+                                                    update() {
+                                                        const end = new Date(this.expiresAt).getTime();
+                                                        const now = new Date().getTime();
+                                                        
+                                                        if (now > end) {
+                                                            this.timeLeft = 'Expired';
+                                                            return;
+                                                        }
+                                                        
+                                                        const diff = end - now;
+                                                        const days = Math.floor(diff / (1000 * 60 * 60 * 24));
+                                                        const hours = Math.floor((diff % (1000 * 60 * 60 * 24)) / (1000 * 60 * 60));
+                                                        const mins = Math.floor((diff % (1000 * 60 * 60)) / (1000 * 60));
+                                                        const secs = Math.floor((diff % (1000 * 60)) / 1000);
+                                                        
+                                                        if (days > 0) {
+                                                            this.timeLeft = `${days}d ${hours}h ${mins}m ${secs}s`;
+                                                        } else if (hours > 0) {
+                                                            this.timeLeft = `${hours}h ${mins}m ${secs}s`;
+                                                        } else if (mins > 0) {
+                                                            this.timeLeft = `${mins}m ${secs}s`;
+                                                        } else {
+                                                            this.timeLeft = `${secs}s`;
+                                                        }
+                                                    }
+                                                 }">
                                                 <div class="text-[10px] font-mono text-zinc-400 truncate group-hover:text-white transition-colors">{{ $mailbox->address }}</div>
-                                                <div class="text-[9px] text-zinc-600 font-bold uppercase mt-1">{{ $mailbox->expires_at?->diffForHumans(['short' => true]) ?? 'Never' }}</div>
+                                                <div class="text-[9px] text-zinc-600 font-bold uppercase mt-1" x-text="timeLeft"></div>
                                             </div>
                                             <svg class="w-4 h-4 text-zinc-700 group-hover:text-pink-500 translate-x-2 opacity-0 group-hover:translate-x-0 group-hover:opacity-100 transition-all" fill="none" viewBox="0 0 24 24" stroke="currentColor"><path stroke-linecap="round" stroke-linejoin="round" stroke-width="2" d="M9 5l7 7-7 7" /></svg>
                                         </button>
diff --git a/tests/Feature/UserTierTest.php b/tests/Feature/UserTierTest.php
index de14418..2b3a1ac 100644
--- a/tests/Feature/UserTierTest.php
+++ b/tests/Feature/UserTierTest.php
@@ -86,4 +86,39 @@ class UserTierTest extends TestCase
         $this->assertTrue($accessibleDomains->contains($publicDomain));
         $this->assertFalse($accessibleDomains->contains($premiumDomain));
     }
+
+    public function test_mailbox_expiration_is_based_on_user_tier()
+    {
+        $domain = Domain::factory()->create(['allowed_types' => ['public'], 'name' => 'public.com']);
+
+        // Test Guest (1 day)
+        \Livewire\Livewire::test(\App\Livewire\Mailbox::class)
+            ->call('autoCreateRandomMailbox');
+        $guestMailbox = \App\Models\Mailbox::latest()->first();
+        $this->assertEquals(1, round(now()->diffInDays($guestMailbox->expires_at)));
+
+        // Test Free (3 days)
+        $freeUser = User::factory()->free()->create();
+        $this->actingAs($freeUser);
+        \Livewire\Livewire::test(\App\Livewire\Mailbox::class)
+            ->call('autoCreateRandomMailbox');
+        $freeMailbox = \App\Models\Mailbox::where('user_id', $freeUser->id)->first();
+        $this->assertEquals(3, round(now()->diffInDays($freeMailbox->expires_at)));
+
+        // Test Pro (7 days)
+        $proUser = User::factory()->pro()->create();
+        $this->actingAs($proUser);
+        \Livewire\Livewire::test(\App\Livewire\Mailbox::class)
+            ->call('autoCreateRandomMailbox');
+        $proMailbox = \App\Models\Mailbox::where('user_id', $proUser->id)->first();
+        $this->assertEquals(7, round(now()->diffInDays($proMailbox->expires_at)));
+
+        // Test Enterprise (14 days)
+        $entUser = User::factory()->enterprise()->create();
+        $this->actingAs($entUser);
+        \Livewire\Livewire::test(\App\Livewire\Mailbox::class)
+            ->call('autoCreateRandomMailbox');
+        $entMailbox = \App\Models\Mailbox::where('user_id', $entUser->id)->first();
+        $this->assertEquals(14, round(now()->diffInDays($entMailbox->expires_at)));
+    }
 }