In my Catalyst app I use func setupMailComposer() { // Check if the device can send email guard MFMailComposeViewController.canSendMail() else { print("Mail services are not available") showMailErrorAlert() return } // Create and configure the mail composer let mailComposeVC = MFMailComposeViewController() mailComposeVC.mailComposeDelegate = self // Set the email details mailComposeVC.setToRecipients(["example@example.com"]) mailComposeVC.setSubject("Subject for your email") mailComposeVC.setMessageBody("This is the body of the email.", isHTML: false) // Attach a file (optional) if let filePath = Bundle.main.path(forResource: "example", ofType: "pdf"), let fileData = try? Data(contentsOf: URL(fileURLWithPath: filePath)) { mailComposeVC.addAttachmentData(fileData, mimeType: "application/pdf", fileName: "example.pdf") } // Present the mail composer self.present(mailComposeVC, animated: true, completion: nil) } Since I have updated to macOS 15.1 the canSendMail() function returns false although I have configured Apple Mail (like before in 15.0 where it worked flawlessly).