React Native Requires Chilkat v11.0.0+

Process New Email by Scanning for Senders

Scan email and save application-selected emails to EML files with unique filenames. React Native

import { Email, EmailBundle, Imap, MessageSet } from '@chilkat/react-native'

async function chilkatExample() {
  // This example assumes the Chilkat API to have been previously unlocked.
  // See Global Unlock Sample for sample code.

  const imap = new Imap();

  // Connect to an IMAP server.
  // Use TLS
  imap.ssl = true;
  imap.port = 993;
  try {
    await imap.connectAsync('imap.example.com');
  } catch {
    console.log(imap.lastErrorText);
    return;
  }

  // Login
  try {
    await imap.loginAsync('myLogin', 'myPassword');
  } catch {
    console.log(imap.lastErrorText);
    return;
  }

  // Select an IMAP mailbox
  try {
    await imap.selectMailboxAsync('Inbox');
  } catch {
    console.log(imap.lastErrorText);
    return;
  }

  // We can choose to fetch UIDs or sequence numbers.
  const fetchUids = true;

  // Fetch messages from the mailbox using a search criteria.
  // This example finds NEW emails: these are emails that have the RECENT flag set, but not the SEEN flag:
  const messageSet = new MessageSet();
  try {
    await imap.queryMbxAsync('NEW', fetchUids, messageSet);
  } catch {
    console.log(imap.lastErrorText);
    return;
  }

  // This example will download headers, and then download
  // the full email for those emails sent from a contact
  // in our database.

  // When downloading headers, each email object contains
  // (obviously) the headers, but the body will be missing.
  // Also, attachments will not be included.  However, it is
  // possible to get information about the attachments
  // as well as the complete size of the email.
  const bundle = new EmailBundle();
  const headersOnly = true;
  try {
    await imap.fetchMsgSetAsync(headersOnly, messageSet, bundle);
  } catch {
    console.log(imap.lastErrorText);
    return;
  }

  // Loop over the email objects...
  const emailHeader = new Email();
  const fullEmail = new Email();
  let i = 0;
  const numEmails = bundle.messageCount;
  while (i < numEmails) {
    bundle.emailAt(i, emailHeader);

    // The sender's email address and name are available
    // in the From, FromAddress, and FromName properties.
    // If the sender is "Chilkat Support <support@chilkatsoft.com",
    // then the From property will hold the entire string.
    // the FromName property contains"Chilkat Support",
    // and the FromAddress property contains "support@chilkatsoft.com";
    console.log(emailHeader.from);
    console.log(emailHeader.fromAddress);
    console.log(emailHeader.fromName);

    // Assume at this point your code checks to see if the sender
    // is one in your contacts database.  If so, this is
    // the code you would write to download the entire
    // email and save it to a file.

    // The ckx-imap-uid header field is added when
    // headers are downloaded.  This makes it possible
    // to get the UID from the email object.
    const uidStr = emailHeader.getHeaderField('ckx-imap-uid');
    const uid = parseInt(uidStr, 10);

    try {
      await imap.fetchEmailAsync(false, uid, true, fullEmail);
    } catch {
      console.log(imap.lastErrorText);
      return;
    }

    // You can use the GenerateFilename method to
    // generate a unique filename...
    const filename = fullEmail.generateFilename();

    // SaveEml saves the entire email, including attachments.
    fullEmail.saveEml(filename);

    console.log('--');

    i++;
  }

  // Disconnect from the IMAP server.
  await imap.disconnectAsync();
}