How to open mail app from Swift

Question

You can use simple mailto: links in iOS to open the mail app.

let email = "[email protected]"
if let url = URL(string: "mailto:\(email)") {
  if #available(iOS 10.0, *) {
    UIApplication.shared.open(url)
  } else {
    UIApplication.shared.openURL(url)
  }    
}

While other answers are all correct, you can never know if the iPhone/iPad that is running your application has the Apple's Mail app installed or not as it can be deleted by the user.

It is better to support multiple email clients. Following code handles the email sending in a more graceful way. The flow of the code is:

• If Mail app is installed, open Mail's composer pre-filled with provided data
• Otherwise, try opening the Gmail app, then Outlook, then Yahoo mail, then Spark, in this order
• If none of those clients are installed, fallback to default mailto:.. that prompts the user to install Apple's Mail app.

Code is written in Swift 5:

    import MessageUI
    import UIKit

    class SendEmailViewController: UIViewController, MFMailComposeViewControllerDelegate {
        
        @IBAction func sendEmail(_ sender: UIButton) {
            // Modify following variables with your text / recipient
            let recipientEmail = "[email protected]"
            let subject = "Multi client email support"
            let body = "This code supports sending email via multiple different email apps on iOS! :)"
            
            // Show default mail composer
            if MFMailComposeViewController.canSendMail() {
                let mail = MFMailComposeViewController()
                mail.mailComposeDelegate = self
                mail.setToRecipients([recipientEmail])
                mail.setSubject(subject)
                mail.setMessageBody(body, isHTML: false)
                
                present(mail, animated: true)
            
            // Show third party email composer if default Mail app is not present
            } else if let emailUrl = createEmailUrl(to: recipientEmail, subject: subject, body: body) {
                UIApplication.shared.open(emailUrl)
            }
        }
        
        private func createEmailUrl(to: String, subject: String, body: String) -> URL? {
            let subjectEncoded = subject.addingPercentEncoding(withAllowedCharacters: .urlQueryAllowed)!
            let bodyEncoded = body.addingPercentEncoding(withAllowedCharacters: .urlQueryAllowed)!
            
            let gmailUrl = URL(string: "googlegmail://co?to=\(to)&subject=\(subjectEncoded)&body=\(bodyEncoded)")
            let outlookUrl = URL(string: "ms-outlook://compose?to=\(to)&subject=\(subjectEncoded)")
            let yahooMail = URL(string: "ymail://mail/compose?to=\(to)&subject=\(subjectEncoded)&body=\(bodyEncoded)")
            let sparkUrl = URL(string: "readdle-spark://compose?recipient=\(to)&subject=\(subjectEncoded)&body=\(bodyEncoded)")
            let defaultUrl = URL(string: "mailto:\(to)?subject=\(subjectEncoded)&body=\(bodyEncoded)")
            
            if let gmailUrl = gmailUrl, UIApplication.shared.canOpenURL(gmailUrl) {
                return gmailUrl
            } else if let outlookUrl = outlookUrl, UIApplication.shared.canOpenURL(outlookUrl) {
                return outlookUrl
            } else if let yahooMail = yahooMail, UIApplication.shared.canOpenURL(yahooMail) {
                return yahooMail
            } else if let sparkUrl = sparkUrl, UIApplication.shared.canOpenURL(sparkUrl) {
                return sparkUrl
            }
            
            return defaultUrl
        }
        
        func mailComposeController(_ controller: MFMailComposeViewController, didFinishWith result: MFMailComposeResult, error: Error?) {
            controller.dismiss(animated: true)
        }
    }

Please note that I intentionally missed out the body for the Outlook app, as it is not able to parse it.

You also have to add following code to Info.plist file that whitelists the URl query schemes that are used.

<key>LSApplicationQueriesSchemes</key>
<array>
    <string>googlegmail</string>
    <string>ms-outlook</string>
    <string>readdle-spark</string>
    <string>ymail</string>
</array>

I'm not sure if you want to switch to the mail app itself or just open and send an email. For the latter option linked to a button IBAction:

    import UIKit
    import MessageUI

    class ViewController: UIViewController, MFMailComposeViewControllerDelegate {

    @IBAction func launchEmail(sender: AnyObject) {

    var emailTitle = "Feedback"
    var messageBody = "Feature request or bug report?"
    var toRecipents = ["[email protected]"]
    var mc: MFMailComposeViewController = MFMailComposeViewController()
    mc.mailComposeDelegate = self
    mc.setSubject(emailTitle)
    mc.setMessageBody(messageBody, isHTML: false)
    mc.setToRecipients(toRecipents)

    self.presentViewController(mc, animated: true, completion: nil)
    }

    func mailComposeController(controller:MFMailComposeViewController, didFinishWithResult result:MFMailComposeResult, error:NSError) {
        switch result {
        case MFMailComposeResultCancelled:
            print("Mail cancelled")
        case MFMailComposeResultSaved:
            print("Mail saved")
        case MFMailComposeResultSent:
            print("Mail sent")
        case MFMailComposeResultFailed:
            print("Mail sent failure: \(error?.localizedDescription)")
        default:
            break
        }
        self.dismissViewControllerAnimated(true, completion: nil)
    }

    }

In Swift 3 you make sure to add import MessageUI and needs conform to the MFMailComposeViewControllerDelegate protocol.

func sendEmail() {
  if MFMailComposeViewController.canSendMail() {
    let mail = MFMailComposeViewController()
    mail.mailComposeDelegate = self
    mail.setToRecipients(["[email protected]"])
    mail.setMessageBody("<p>You're so awesome!</p>", isHTML: true)

    present(mail, animated: true)
  } else {
    // show failure alert
  }
}

Protocol:

func mailComposeController(_ controller: MFMailComposeViewController, didFinishWith result: MFMailComposeResult, error: Error?) {
  controller.dismiss(animated: true)
}

For Swift 4.2+ and iOS 9+

let appURL = URL(string: "mailto:[email protected]")!

if #available(iOS 10.0, *) {
    UIApplication.shared.open(appURL, options: [:], completionHandler: nil)
} else {
    UIApplication.shared.openURL(appURL)
}

Replace [email protected] with your desired email address.

You can also include a subject field, a message, and multiple recipients in the To, Cc, and Bcc fields:

mailto:[email protected][email protected]&subject=Greetings%20from%20Cupertino!&body=Wish%20you%20were%20here!

Swift 2, with availability check:

import MessageUI

if MFMailComposeViewController.canSendMail() {
    let mail = MFMailComposeViewController()
    mail.mailComposeDelegate = self
    mail.setToRecipients(["[email protected]"])
    mail.setSubject("Bla")
    mail.setMessageBody("<b>Blabla</b>", isHTML: true)
    presentViewController(mail, animated: true, completion: nil)
} else {
    print("Cannot send mail")
    // give feedback to the user
}


// MARK: - MFMailComposeViewControllerDelegate

func mailComposeController(controller: MFMailComposeViewController, didFinishWithResult result: MFMailComposeResult, error: NSError?) {
    switch result.rawValue {
    case MFMailComposeResultCancelled.rawValue:
        print("Cancelled")
    case MFMailComposeResultSaved.rawValue:
        print("Saved")
    case MFMailComposeResultSent.rawValue:
        print("Sent")
    case MFMailComposeResultFailed.rawValue:
        print("Error: \(error?.localizedDescription)")
    default:
        break
    }
    controller.dismissViewControllerAnimated(true, completion: nil)
}