A Swift framework for working with emails

I try to access my IMAP server with this code, which is based on your demo code:

`

import Foundation
import Postal

class MailManagerPostal {
    var configuration: Configuration!
    
    fileprivate lazy var postal: Postal = Postal(configuration: self.configuration)
    fileprivate var messages: [FetchResult] = []
    
    init(hostname: String, userName: String, password: String) {
        log.debug("init called...")
        
        configuration = Configuration(hostname: hostname, port: 993, login: userName, password: .plain(password), connectionType: .tls, checkCertificateEnabled: false)

        log.debug("configuration created: \(self.configuration.description)")
        
        postal.connect(timeout: Postal.defaultTimeout, completion: { [weak self] result in
            log.debug("postal.connect completed.")
            switch result {
            case .success:
                log.debug("fetching messages now.")
                
                let indexset = IndexSet(0...100000)
                
                self?.postal.fetchMessages("INBOX", uids: indexset, flags: [ .fullHeaders ], onMessage: { message in
                    log.debug("message : \(message.header)")
                    self?.messages.insert(message, at: 0)
                }, onComplete: { error in
                    if let error = error {
                        log.error("fetch failed: \((error as NSError).localizedDescription)")
                    } else {
                        log.debug("connection successful")
                    }
                    log.debug("fetch complete.")
                })
                
            case .failure(let error):
                log.error("connection failed: \((error as NSError).localizedDescription)")
            }
        })
        log.debug("init finished.")
    }
}

`

Problem: The last message I see is "fetching messages now.". Then nothing happens any more. What's happening here? Where is my mistake? The credentials I use work with using mailcode2 without a problem.

Some more questions:

• How can I debug the IMAP requests?
• Where can I find a documentation of the API?
• Can I manipulate message, especially add custom headers to a message (or take a message, add custom headers, write it as a new message to the server and delete the old one...)?

It appears that giving an IndexSet to fetchMessages() with a single index actually tries to fetch 2 messages. This also means that fetchLast() fails.

i.e.

   let indexset = IndexSet(integer: 2750)
   postal.fetchMessages("INBOX", uids: indexset, flags: [ .fullHeaders ], ...

actually tries to fetch messages 2750 and 2751.

I'm struggling to find the right API to use to retrieve the message body. If I take the raw data from a message part, I can convert it to a String but it has extraneous characters. Is there an API to use to get the contents of a message?

As mentioned in the recent XCode 10.2 PR thread: https://github.com/snipsco/Postal/pull/83#issuecomment-485564820

• Result module was removed but is still referenced in Postal.podspec. I don't use pods in my project so I'm not sure what issues this may cause.

• Postal-iOS framework has 7 swift language-related warnings:

When compiling a project with Postal installed via CocoaPods, the build fails in Extensions+Parsing.swift with error Use of extraneous '&' in lines 51, 55, 60 and 64

Breaks here

❌  /Users/distiller/theios/Pods/Postal/dependencies/module.modulemap:2:12: header 'build/ios/include/libetpan/libetpan.h' not found

    header "build/ios/include/libetpan/libetpan.h"
           ^



❌  /Users/distiller/theios/Pods/Postal/Postal/Address+Parsing.swift:26:8: could not build Objective-C module 'libetpan'

import libetpan
       ^

Any ideas how to fix, it works locally.

Hi,

I'd like to use ReactiveCocoa 6.0.0 (using ReactiveSwift 2.0.0) in my application, but found out (by a dependency problem with Result 3.1 vs. 3.2), that Postal uses ReactiveSwift 1.

Is there any chance, that Postal works with ReactiveSwift 2 / ReactiveCocoa 6 / Result 3.2.3 ?

Regards, Eike

Problem: We have to optimize the NSIndexSet.enumerate(batchSize: Int) because of too much complexity in it -> O(n)

Example: If we try to fetch all emails we would do something like:

let range = NSRange(location: 1, length: Int.max - 1)
let indexSet = NSIndexSet(indexesInRange: range)

var results = [FetchResult]()
try imapSession.fetchMessages("INBOX", set: IMAPIndexes.indexes(indexSet), flags: [ .fullHeaders ]) { _ in }

Current result: It takes too much time for a provider that have a batchSize == Int.max to create the only one indexset needed for the fetch.

Expected result: Instant fetch

Possible solution: We could try to use the Strideable protocol instead or simply optimize inside the method.

It was asked here by someone: https://stackoverflow.com/questions/41155748/how-get-mail-content-using-postal-swift-framework

Please let me know if there are any document or dev guide to start? Or how to find out?

Hi klevefre,

you wrote about debugging Postal:

You can set a closure on a Postal instance to have IMAP logs: let postal = Postal(configuration: ...) postal.logger { log in print(log) }

Unfortunately this doesn't work in my code. I get the compiler error message "Cannot call value of non-function type 'logger?'

This is my code:

init(hostname: String, userName: String, password: String) {
    log.debug("init called...")
    
    configuration = Configuration(hostname: hostname, port: 993, login: userName, password: .plain(password), connectionType: .tls, checkCertificateEnabled: false)
    
    let postal: Postal = Postal(configuration: configuration)
    postal.logger { log in
        print(log)
    }
[...]

What's wrong with my code? It's exactly as you wrote...?

I have created a mail app using Postal Framework and my mail server send the message to app with different type data, so how I know a data in body is encode/decode by type? In my example I don't know data should encode with NSUTF8StringEncoding or NSISO2022JPStringEncoding :(

msg.body?.allParts.forEach({ (singlePart) in
    let meesage = String.init(data: (singlePart.data?.rawData)!, encoding: NSUnicodeStringEncoding)
    if singlePart.mimeType == MimeType.textPlain {
        mailInfo.messageDescription = meesage?.stringByTrimmingCharactersInSet(NSCharacterSet.whitespaceAndNewlineCharacterSet()) ?? ""
    } else if singlePart.mimeType == MimeType.textHtml {
        mailInfo.message = meesage ?? ""
    }
})

Thanks for support!

Postal looks fantastic, and the approach of interfacing with libetpan directly is the way to go. However I'm saddened to see there's been no activity since 2017 - is this project still supported by its creators? MailCore stopped working recently and I'm saddened to see another great effort has stopped as well.

I was wondering if Postal supports Push (i.e. the user's email server informing an app that uses Postal about new messages). As far as I understand, this is known under the name IDLE (https://tools.ietf.org/html/rfc2177).

I didn't find any traces of it in the examples or in documentation/roadmap, so I thought I would ask how big the interest is in implementing it or if there have been any plans already.

I have also checked libetpan and it seems like it's available there. If implementing it is (in your opinion) uncomplicated enough for me to try it without substantial C experience, I'd love a tip on where to start.

Otherwise, I would greatly appreciate any advice on what other packages I might use for that functionality in a macOS app. I'm writing it in Swift, but wouldn't mind using a package from another language, if the interop works. From what I found, MailCore or libetpan could be my only options, would be interested to find out otherwise.

Thanks for any advice/help and to the contributors for their work.

Whenever I try to connect to any e-mail account, I am getting a certificate error.

error: certificate. The operation couldn’t be completed. (Postal.PostalError error 4.)

Hello,

I am new in this library and I hope I get help here. I use Swift 5.

When I use the following code I get only "ENDED" but nothing else back in the console. No error message. What I am doing wrong?

A happy New Year to all.

Greetings, Sven

import Foundation      
import Postal  
    
let postal : Postal = Postal(configuration: Configuration(hostname: "email.none.none", port: 993, login: "[email protected]", password: .plain("test"), connectionType: .tls, checkCertificateEnabled: true, batchSize: 1000, spamFolderName: "junk"))  
    
func getEmail() {  
    let indexset = IndexSet(integer: 1)  
    postal.fetchMessages("INBOX", uids: indexset, flags: [ .headers ], onMessage: { email in  
        print("new email received: \(email)")  
    }, onComplete: { error in  
        if error == error {  
            print("an error occured: \(error)")  
        }  
    })  
}  
    
postal.connect { result in  
    switch result {  
    case .success:  
        getEmail()  
    case .failure(let error):  
        print("error: \(error)")  
    }  
}  
    
print("ENDED")