Swift-SMTP

The TLSMode enum defines how the connection handles encryption:

• .normal: Upgrades the connection to TLS if the STARTLS command is received; otherwise, sends mail without security.
• .ignoreTLS: Sends mail over plaintext and ignores STARTTLS commands and TLS options. This may throw an error if the server requires TLS.
• .requireTLS: Only sends mail after a successful initial TLS connection. The connection fails if TLS cannot be established. Note: When using this mode, you will likely need to adjust the port (e.g., to 465) depending on your server.
• .requireSTARTTLS: Expects a STARTTLS command from the server and requires the connection to be upgraded. Throws an error if the server does not issue STARTTLS.

The accessToken parameter was removed in version 4.0.0. If you are using the XOAUTH2 authorization method, you must pass your access token into the password parameter instead.

let smtp = SMTP(
    hostname: "smtp.gmail.com",
    email: "example@gmail.com",
    password: "accessToken",
    authMethods: [.xoauth2]
)

To add SwiftSMTP to your project, add it as a dependency in your Package.swift file. Note that the dependency name is SwiftSMTP (without a hyphen). After updating your Package.swift, run swift package generate-xcodeproj in your project root to fetch dependencies and create the Xcode project.

// swift-tools-version:4.0

import PackageDescription

let package = Package(
    name: "MyProject",
    products: [
        .library(
            name: "MyProject",
            targets: ["MyProject"]),
    ],
    dependencies: [
        .package(url: "https://github.com/Kitura/Swift-SMTP", .upToNextMinor(from: "5.1.0")),    // add the dependency
    ],
    targets: [
        .target(
            name: "MyProject",
            dependencies: ["SwiftSMTP"]),
        .testTarget(
            name: "MyProjectTests",
            dependencies: ["MyProject"]),
    ]
)

To send an email, create a Mail object and use the SMTP instance's send method. You define sender and receiver identities using the Mail.User struct. You can also include cc and bcc recipients.

let drLight = Mail.User(name: "Dr. Light", email: "drlight@gmail.com")
let megaman = Mail.User(name: "Megaman", email: "megaman@gmail.com")

let mail = Mail(
    from: drLight,
    to: [megaman],
    subject: "Humans and robots living together in harmony and equality.",
    text: "That was my ultimate wish."
)

smtp.send(mail) { (error) in
    if let error = error {
        print(error)
    }
}

You can pass an array of Mail objects to the send method. This method provides two optional callbacks:

• progress: Called after each individual mail is attempted. Provides the mail attempted and an optional error.
• completion: Called after the entire batch is processed. Provides sent (array of successfully sent Mail objects) and failed (array of (Mail, Error) tuples).

let mail1: Mail = //...
let mail2: Mail = //...

smtp.send([mail1, mail2],
    progress: { (mail, error) in
        // Called after each mail is sent
    },
    completion: { (sent, failed) in
        // Called after all mails have been sent
    }
)

Starting with version 5.0.0, the SMTP struct no longer uses a useTLS: Bool parameter. Instead, it uses a TLSMode enum to provide more granular control over connection security. The default port has also changed to 587.

// Example of using TLSMode for connection security
let smtp = SMTP(
    hostname: "smtp.example.com",
    email: "user@example.com",
    password: "password",
    port: 587,
    tlsMode: .requireTLS
)

In version 4.0.0 and later, the User struct is nested within the Mail struct to prevent namespace collisions. To create a user, use Mail.User.

let sender = Mail.User(name: "Sloth", email: "sloth@gmail.com")

The SMTP struct is the primary handle for sending emails. By default, it connects on port 587 and requires a TLS connection via STARTTLS.

Use the following initializer to configure the connection:

public init(hostname: String, 
            email: String, 
            password: String, 
            port: Int32 = 587, 
            tlsMode: TLSMode = .requireSTARTTLS, 
            tlsConfiguration: TLSConfiguration? = nil, 
            authMethods: [AuthMethod] = [], 
            domainName: String = "localhost", 
            timeout: UInt = 10)

import SwiftSMTP

let smtp = SMTP(
    hostname: "smtp.gmail.com",     // SMTP server address
    email: "user@gmail.com",        // username to login
    password: "password"            // password to login
)