Daily Spam Digest for Google Apps Script

SpamDigest.gs

// Daily Spam Digest for Gmail.
// Creates a single digest email with deep links to any spam messages you received that day
// so you can easily check for false positives and retrieve them

// Usage:
// 1. Replace EMAIL with your email
// 2. Create trigger whenever you want to get the email
// 3. If you set your trigger for the morning, you likely want to edit the date settings so you don't miss any
function run() {
  const EMAIL = '[email protected]';
  
  const date = new Date();
  const day = date.getDate();
  const month = date.getMonth() + 1;
  const year = date.getFullYear();
  const dateString = [year, month, day].join('/');
  const results = GmailApp.search(['in:spam in:unread after:', dateString].join(' '));
  
  var threadsByRecipient = {};
  if (!results.length) { return; }
  
  results.forEach(function(thread) {
    const lastMessage = thread.getMessages()[thread.getMessageCount() - 1];
    const recipient = getTo(lastMessage);
    if (!threadsByRecipient[recipient]) {
      threadsByRecipient[recipient] = [];
    }
    threadsByRecipient[recipient].push(thread);
  });  
  
  var body = '<table>';
  for (var recipient in threadsByRecipient) {
    var threads = threadsByRecipient[recipient];
    body += '<tr></tr>';
    body += '<tr><th colspan=3 style="text-align:left;">';
    body += ['<h2>', unlink(escapeEmail(recipient)), '</h2></a>'].join('');
    body += '</th></tr>';
    threads.forEach(function(thread) {
      body += renderThread(thread);
    })
  }
  body += '</table>';
  GmailApp.sendEmail(EMAIL, "Daily Spam Digest", body.replace(/<[^>]*>/g, ''), {
    htmlBody: body,
  });
}

function unlink(string) {
  return ['<a style="color:black;text-decoration:none;">', string, '</a>'].join('');
}

function getTo(message) {
  try {
    return message.getRawContent().match(/^To:.*<(.*)>$/m)[1];
  } catch(error) {
    return message.getTo();
  }
}

function getFrom(message) {
  try {
    return message.getRawContent().match(/^From:(.*)$/m)[1].trim();
  } catch(error) {
    return message.getFrom();
  }
}

function splitFrom(from) {
  try {
    const midpoint = from.indexOf(' <');
    const name = from.substr(0, midpoint);
    const email = from.substr(midpoint + 2, from.length - midpoint - 2);
    return {name: name, email: email};
  } catch(error) {
    return {name: name, email: ''};
  }
}

function escapeEmail(email) {
  return email.replace('<', '&lt;').replace('>', '&gt;');
}

function renderThread(thread) {
  const subject = thread.getFirstMessageSubject();
  const lastMessage = thread.getMessages()[thread.getMessageCount() - 1];
  const sender = splitFrom(getFrom(lastMessage));
  const link = 'https://mail.google.com/mail/u/0/#all/' + lastMessage.getId();
  return tr([
    td(unlink(truncate(sender.name, 15))),
    td(unlink(truncate(sender.email, 25, true)), true),
    td('<a href="' + link + '">' + subject + '</a>'),
  ]);
}

function truncate(string, length, rtl) {
  if (string.length < length) {
    return string;
  }
  else {
    const truncated = rtl ?
      '...' + string.substr(string.length - length, length) :
      string.substr(0, length) + '...'
    ;
    return '<span title="' + string + '">' + truncated + '</span>';
  }
}
    
function tr(elements) {
  return ['<tr>', elements.join(''), '</tr>'].join('');
}

function td(string, rtl) {
  return ['<td style="text-align:' + (rtl ? 'right' : 'left') + '">', string, '</td>'].join('');
}