imap_client

An interface to get emails via the imap protocol (version 4rev1)

This interface implements the IMAP protocol (version 4 rev 1) as described in rfc 3501. This package gives easy access to all commands and automatically analyzes responses.

Supported extensions:

  • RFC 2177: IMAP4 IDLE command

This package is made available under the GNU General Public License v3.0.

Usage

This example connects the client to an imap server:

import 'package:imap_client/imap_client.dart';

main() async {
  ImapClient client = new ImapClient();
  
  await client.connect("imap.gmail.com", 993, true);
}

All commands are async methods that can be awaited for. On completion, most return an enum ImapTaggedResponse, which can be either:

  • OK: success
  • NO: command was unsuccessful
  • BAD: command not accepted by the server

Sometimes, there are commands which have other return data, like fetch or list.

To select a folder, a simple call to getFolder() is sufficient:

import 'package:imap_client/imap_client.dart';

main() async {
  ImapClient client = new ImapClient();
  
  await client.connect("imap.gmail.com", 993, true);
  
  ImapFolder inbox = client.getFolder("inbox");
}

This ImapFolder instance allows for actions in this specific folder. Folders can only exist once per name, so another call to ImapClient.getFolder() with the same name will return the same ImapFolder instance! If an instance is no longer needed, it can be marked for garbage collection via ImapFolder.destroy(). This will free up some ram and should especially be considered when working with many folders.

There are two types of handlers that are highly suggested to be implemented:

ALERT handler:
void Function(String message)

The messages passed to this function are directly from the server and must be shown to the user (as defined in the protocol).

EXPUNGE handler:
void Function(int number)

This function receives message numbers of messages that have been deleted.

Both can be set directly via the client instance, either via client.expungeHandler = ... or client.alertHandler = ...

ImapFolder.store(), ImapFolder.fetch() and ImapFolder.copy() need messages to work with. Those messages can either be provided via the optional messageId parameter, or if ranges are needed, via the optional messageIdRanges. One of the two must always be given.

Ranges have the following format: start:end, whereas end can also be *, which matches the highest possible number as determined by the server. This means that 1:* would match every mail in this folder.

To use message uids instead of relative numbers, the optional parameter uid can be set to true. Please note that responses from the server will also use uids instead of relative numbers.

Example:

await inbox.fetch(["BODY"], messageIds: [1]);

Authentication

The last important thing would be logging in. There are three possible ways:

Preauth

Preauth means that the client is already registered, this might be because credentials were already submitted via the url on connect.

Login

The login command takes a username and password as parameters.

await client.login("username", "password");
Authenticate

The authenticate command is used for any other authentication mechanisms. It takes an ImapSaslMechanism object and logs in via the mechanism defined there. "login" and "plain" are both already implemented, a short walk through on how to create a custom mechanism can be found in the wiki.

await client.authenticate(new ImapPlainAuth("username", "password"));

Closing the connection

To close the connection, logout can either be called in a folder or the client itself.

Features and bugs

Please file feature requests and bugs at the issue tracker.

Libraries

imap_client
This library provides the interface to get emails via the imap protocol.