diff --git a/application/controllers/Logbooks.php b/application/controllers/Logbooks.php
index 7f939cb88..48156a4ba 100644
--- a/application/controllers/Logbooks.php
+++ b/application/controllers/Logbooks.php
@@ -316,7 +316,12 @@ class Logbooks extends CI_Controller {
 		// Add permission
 		$result = $this->logbooks_model->add_logbook_permission($logbook_id, $user->user_id, $permission_level);
 		
-		if ($result) {
+		if ($result['success']) {
+			// Send email notification if this is a new user being added
+			if ($result['is_new'] && $user->user_email != "") {
+				$this->send_logbook_shared_email($logbook_id, $user, $permission_level);
+			}
+			
 			// Return updated collaborators list
 			$data['collaborators'] = $this->logbooks_model->list_logbook_collaborators($logbook_id);
 			$data['is_owner'] = $this->logbooks_model->is_logbook_owner($logbook_id);
@@ -383,4 +388,68 @@ class Logbooks extends CI_Controller {
 		}
 	}
 
+	private function send_logbook_shared_email($logbook_id, $user, $permission_level) {
+		// Send email notification when a logbook is shared with a user
+		
+		// Check if email is configured
+		if ($this->optionslib->get_option('emailProtocol') == '') {
+			log_message('info', 'Email not configured - skipping logbook sharing notification');
+			return;
+		}
+		
+		// Get logbook details
+		$logbook_query = $this->logbooks_model->logbook($logbook_id);
+		if ($logbook_query->num_rows() == 0) {
+			return;
+		}
+		$logbook = $logbook_query->row();
+		
+		// Get owner information
+		$owner_query = $this->user_model->get_by_id($this->session->userdata('user_id'));
+		if ($owner_query->num_rows() == 0) {
+			return;
+		}
+		$owner = $owner_query->row();
+		
+		// Load email library
+		$this->load->library('email');
+		
+		// Configure SMTP if needed
+		if ($this->optionslib->get_option('emailProtocol') == "smtp") {
+			$config = Array(
+				'protocol' => $this->optionslib->get_option('emailProtocol'),
+				'smtp_crypto' => $this->optionslib->get_option('smtpEncryption'),
+				'smtp_host' => $this->optionslib->get_option('smtpHost'),
+				'smtp_port' => $this->optionslib->get_option('smtpPort'),
+				'smtp_user' => $this->optionslib->get_option('smtpUsername'),
+				'smtp_pass' => $this->optionslib->get_option('smtpPassword'),
+				'crlf' => "\r\n",
+				'newline' => "\r\n"
+			);
+			$this->email->initialize($config);
+		}
+		
+		// Prepare email data
+		$email_data = array(
+			'user_callsign' => $user->user_callsign,
+			'owner_callsign' => $owner->user_callsign,
+			'logbook_name' => $logbook->logbook_name,
+			'permission_level' => $permission_level,
+			'base_url' => base_url(),
+		);
+		
+		$message = $this->load->view('email/logbook_shared.php', $email_data, TRUE);
+		
+		$this->email->from($this->optionslib->get_option('emailAddress'), $this->optionslib->get_option('emailSenderName'));
+		$this->email->to($user->user_email);
+		$this->email->subject('Cloudlog - Logbook Shared With You');
+		$this->email->message($message);
+		
+		if (!$this->email->send()) {
+			log_message('error', 'Failed to send logbook sharing email to ' . $user->user_email . '. Error: ' . $this->email->print_debugger());
+		} else {
+			log_message('info', 'Logbook sharing notification sent to ' . $user->user_email);
+		}
+	}
+
 }
diff --git a/application/controllers/Options.php b/application/controllers/Options.php
index 13ff76ab1..67bfa2a3c 100644
--- a/application/controllers/Options.php
+++ b/application/controllers/Options.php
@@ -379,12 +379,14 @@ class Options extends CI_Controller {
 			$this->email->message($message);
 
 			if (! $this->email->send()){
-				$this->session->set_flashdata('testmailFailed', $this->lang->line('options_send_testmail_failed'));
+				// Log the error for debugging
+				log_message('error', 'Test email failed to send. Error: ' . $this->email->print_debugger());
+				$this->session->set_flashdata('testmailFailed', $this->lang->line('options_send_testmail_failed') . ' Check application logs for details.');
 			} else {
 				$this->session->set_flashdata('testmailSuccess', $this->lang->line('options_send_testmail_success'));
 			}
 		} else {
-			$this->session->set_flashdata('testmailFailed', $this->lang->line('options_send_testmail_failed'));
+			$this->session->set_flashdata('testmailFailed', $this->lang->line('options_send_testmail_failed') . ' No email address found in your account settings.');
 		}
 		
 		redirect('/options/email');
diff --git a/application/models/Logbooks_model.php b/application/models/Logbooks_model.php
index 66a30d8e2..5a2d54737 100644
--- a/application/models/Logbooks_model.php
+++ b/application/models/Logbooks_model.php
@@ -422,6 +422,7 @@ class Logbooks_model extends CI_Model {
 	public function add_logbook_permission($logbook_id, $user_id, $permission_level = 'read') {
 		// Add a user to a logbook with specified permission level
 		// Only owner or admin can add users
+		// Returns array with 'success' and 'is_new' keys
 		
 		$clean_logbook_id = $this->security->xss_clean($logbook_id);
 		$clean_user_id = $this->security->xss_clean($user_id);
@@ -430,13 +431,13 @@ class Logbooks_model extends CI_Model {
 		// Validate permission level
 		$valid_permissions = array('read', 'write', 'admin');
 		if (!in_array($clean_permission, $valid_permissions)) {
-			return false;
+			return array('success' => false, 'is_new' => false);
 		}
 		
 		// Check if current user has admin rights or is owner
 		if (!$this->is_logbook_owner($clean_logbook_id) && 
 			!$this->check_logbook_is_accessible($clean_logbook_id, 'admin')) {
-			return false;
+			return array('success' => false, 'is_new' => false);
 		}
 		
 		// Check if permission already exists
@@ -444,6 +445,8 @@ class Logbooks_model extends CI_Model {
 		$this->db->where('user_id', $clean_user_id);
 		$existing = $this->db->get('station_logbooks_permissions');
 		
+		$is_new = ($existing->num_rows() == 0);
+		
 		if ($existing->num_rows() > 0) {
 			// Update existing permission
 			$data = array(
@@ -463,7 +466,7 @@ class Logbooks_model extends CI_Model {
 			$this->db->insert('station_logbooks_permissions', $data);
 		}
 		
-		return true;
+		return array('success' => true, 'is_new' => $is_new);
 	}
 
 	public function remove_logbook_permission($logbook_id, $user_id) {
diff --git a/application/views/email/logbook_shared.php b/application/views/email/logbook_shared.php
new file mode 100644
index 000000000..b25b61fec
--- /dev/null
+++ b/application/views/email/logbook_shared.php
@@ -0,0 +1,43 @@
+Hi <?php echo $user_callsign; ?>,
+
+<?php echo $owner_callsign; ?> has shared a logbook with you on Cloudlog.
+
+Logbook: <?php echo $logbook_name; ?>
+
+Permission Level: <?php echo ucfirst($permission_level); ?>
+
+<?php if ($permission_level == 'read') { ?>
+You can now view this logbook and its QSOs.
+<?php } elseif ($permission_level == 'write') { ?>
+You can now view, add, edit, and delete QSOs in this logbook, as well as manage station locations.
+<?php } elseif ($permission_level == 'admin') { ?>
+You have full administrative access to this logbook, including the ability to manage other users' access.
+<?php } ?>
+
+Getting Started:
+<?php if ($permission_level != 'read') { ?>
+1. Log into your Cloudlog account at: <?php echo $base_url; ?>
+
+2. Create a Station Location using the shared callsign (<?php echo $owner_callsign; ?>):
+   - Go to Station Locations and click "Create Station Location"
+   - Enter the callsign: <?php echo $owner_callsign; ?>
+   - Enter the location details (gridsquare, DXCC, etc.)
+   - Save the station location
+
+3. Link your Station Location to this logbook:
+   - Go to Logbooks > Edit "<?php echo $logbook_name; ?>"
+   - In the "Link Location" section, select your newly created station location
+   - Click "Link Location"
+
+4. You're ready to start logging! Set this logbook as active from the Logbooks page.
+<?php } else { ?>
+1. Log into your Cloudlog account at: <?php echo $base_url; ?>
+
+2. Go to Logbooks and set "<?php echo $logbook_name; ?>" as your active logbook to view the QSOs.
+<?php } ?>
+
+If you have any questions, please contact <?php echo $owner_callsign; ?>.
+
+Regards,
+
+Cloudlog.
diff --git a/application/views/options/email.php b/application/views/options/email.php
index 20e16eef6..ffa8ce942 100644
--- a/application/views/options/email.php
+++ b/application/views/options/email.php
@@ -112,10 +112,18 @@
                         <input class="btn btn-primary" type="submit" value="<?php echo lang('options_save'); ?>" />
                     </form>
                     <br>
-                    <?php echo form_open('options/sendTestMail'); ?>
-                        <input class="btn btn-primary" type="submit" value="<?php echo lang('options_send_testmail'); ?>" />
+                    <?php echo form_open('options/sendTestMail', ['id' => 'testMailForm']); ?>
+                        <input class="btn btn-primary" id="testMailBtn" type="submit" value="<?php echo lang('options_send_testmail'); ?>" />
+                        <span id="testMailSpinner" class="spinner-border spinner-border-sm ms-2" role="status" aria-hidden="true" style="display: none;"></span>
                         <small class="form-text text-muted"><?php echo lang('options_send_testmail_hint'); ?></small>
                     </form>
+                    
+                    <script>
+                    document.getElementById('testMailForm').addEventListener('submit', function() {
+                        document.getElementById('testMailBtn').disabled = true;
+                        document.getElementById('testMailSpinner').style.display = 'inline-block';
+                    });
+                    </script>
                 </div>
             </div>
 		</div>