send mail via MailCore2

SendMail.swift

import Foundation

struct SendMail {
    
    static let HOSTNAME = "smtp.gmail.com"
    static let PORT: UInt32 = 465
    static let USERNAME = "HOGEHOGE@gmail.com"
    static let PASSWORD = "PASSWORD"
    static let FROM = "HOGEHOGE@gmail.com"

    static func send(subject: String, message: String, to email: [String], complection: ((Error?) -> Void)?) {
        let smtpSession = MCOSMTPSession()
        
        smtpSession.hostname = HOSTNAME
        smtpSession.port = PORT
        smtpSession.username = USERNAME
        smtpSession.password = PASSWORD
        smtpSession.authType = .saslPlain
        smtpSession.connectionType = .TLS
        
        let builder = MCOMessageBuilder()
        builder.header.from = MCOAddress(displayName: nil, mailbox: FROM)
        builder.header.to = email.map({ MCOAddress(displayName: nil, mailbox: $0) as Any })
        builder.header.subject = subject
        builder.htmlBody = message
        
        let data = builder.data()
        
        let sendOperation = smtpSession.sendOperation(with: data)
        sendOperation?.start({ (error) in
            complection?(error)
        })
    }
}