We solved this "the hard way" by not using the shared services, but the postfix utility. Note that postfix must be running and correctly configured before the following code can take effect.
Why do this the hard way? well, it is a slightly more 'universal' solution that should work (or can be modified easily) on other platforms than macOS. Also, it does not depend on 'mail'.
Note that this also uses our Log facility, but you should be able to easily extract the code you need.
/// This queue/thread will be used to transfer the mails.
fileprivate let mailQueue = DispatchQueue.global(qos: .background)
/// Sends an email using the postfix unix utility.
///
/// - Note: Ths function only works if postfix is running (and set up correctly)
///
/// - Parameters:
/// - mail: The email to be transmitted. It should -as a minimum- contain the To, From and Subject fields.
/// - domainName: The domain this email is sent from, used for logging purposes only.
public func sendEmail(_ mail: String, domainName: String) {
// Do this on a seperate queue in the background so this operation is non-blocking.
mailQueue.async { [mail, domainName] in
// Ensure the mail is ok
guard let utf8mail = mail.data(using: .utf8), utf8mail.count > 0 else {
Log.atDebug?.log("No mail present")
return
}
let options: Array<String> = ["-t"] // This option tells sendmail to read the from/to/subject from the email string itself.
let errpipe = Pipe() // should remain empty
let outpipe = Pipe() // should remain empty (but if you use other options you may get some text)
let inpipe = Pipe() // will be used to transfer the mail to sendmail
// Setup the process that will send the mail
let process = Process()
if #available(OSX 10.13, *) {
process.executableURL = URL(fileURLWithPath: "/usr/sbin/sendmail")
} else {
process.launchPath = "/usr/sbin/sendmail"
}
process.arguments = options
process.standardError = errpipe
process.standardOutput = outpipe
process.standardInput = inpipe
// Start the sendmail process
let data: Data
do {
Log.atDebug?.log("\n\(mail)")
// Setup the data to be sent
inpipe.fileHandleForWriting.write(utf8mail)
// Start the sendmail process
if #available(OSX 10.13, *) {
try process.run()
} else {
process.launch()
}
// Data transfer complete
inpipe.fileHandleForWriting.closeFile()
// Set a timeout. 10 seconds should be more than enough.
let timeoutAfter = DispatchTime(uptimeNanoseconds: DispatchTime.now().uptimeNanoseconds + UInt64(10000) * 1000000)
// Setup the process timeout on another queue
DispatchQueue.global().asyncAfter(deadline: timeoutAfter) {
[weak process] in
Log.atDebug?.log("Sendmail Timeout expired, process \(process != nil ? "is still running" : "has exited already")")
process?.terminate()
}
// Wait for sendmail to complete
process.waitUntilExit()
Log.atDebug?.log("Sendmail terminated")
// Check termination reason & status
if (process.terminationReason == .exit) && (process.terminationStatus == 0) {
// Exited OK, return data
data = outpipe.fileHandleForReading.readDataToEndOfFile()
if data.count > 0 {
Log.atDebug?.log("Unexpectedly read \(data.count) bytes from sendmail, content: \(String(data: data, encoding: .utf8) ?? "")")
} else {
Log.atDebug?.log("Sendmail completed without error")
}
} else {
// An error of some kind happened
Log.atError?.log("Sendmail process terminations status = \(process.terminationStatus), reason = \(process.terminationReason.rawValue )")
let now = dateFormatter.string(from: Date())
Log.atError?.log("Sendmail process failure, check domain (\(domainName)) logging directory for an error entry with timestamp \(now)")
// Error, grab all possible output and create a file with all error info
let e = errpipe.fileHandleForReading.readDataToEndOfFile()
let d = outpipe.fileHandleForReading.readDataToEndOfFile()
let dump =
"""
Process Termination Reason: \(process.terminationReason.rawValue)
Sendmail exit status: \(process.terminationStatus)
Details:
- Sendmail Executable : /usr/sbin/sendmail
- Sendmail Options : -t
- Sendmail Timeout : 10,000 mSec
- Sendmail Error output: \(e.count) bytes
- Sendmail Output : \(d.count) bytes
Below the output of sendmail is given in the following block format:
(----- Email input -----)
...
(----- Standard Error -----)
...
(----- Standard Out -----)
...
(----- End of output -----)
(----- Email input -----)
\(mail)
(----- Standard Error -----)
\(String(bytes: e, encoding: .utf8) ?? "")
(----- Standard Out -----)
\(String(bytes: d, encoding: .utf8) ?? "")
(----- End of output -----)
"""
let errorFileName = "sendmail-error-log-" + now
if
let errorFileUrl = Urls.domainLoggingDir(for: domainName)?.appendingPathComponent(errorFileName).appendingPathExtension("txt"),
let dumpData = dump.data(using: .utf8),
((try? dumpData.write(to: errorFileUrl)) != nil) {
} else {
Log.atError?.log("Cannot create sendmail error file, content is: \n\(dump)\n")
}
}
} catch let error {
Log.atError?.log("Exception occured during sendmail execution, message = \(error.localizedDescription)")
}
}
}
This routine should be called with a string formatted like:
let email: String =
"""
To: \(emailAddress)
From: \(fromAddress)
Content-Type: text/html;
Subject: Confirm Account Creation at \(domain.name)\n
\(message)
"""
