Introducing MailBots: Bots For Email

Reilly Sweetland
Published in
6 min readJan 29, 2019


MailBots is a platform for creating bots on top of email — only email. We are solving the unique challenges and unlocking opportunities that email-based bots present and packaging it all into an easy to use bot-building platform. Your email-based bot / personal assistant / AI is coming soon and we can’t wait to help you create it. 🙌🤖🚀

We are at the beginning of an era when human and computer actions are almost impossible to tell apart. We invite AI assistants into our homes, have them drive our cars and diagnose diseases. While concerns of idle humans amidst an AI-dominated workforce occupy the news headlines, another question is more likely to occupy our day-to-day thoughts: How can I leverage technology to make myself and my team more productive?

Email is a prime target.

Premise: Email Is Not Broken

Email is the lowest common denominator of digital communication — not everyone likes Twitter, Facebook or SMS. But nearly everyone, love it or hate it, has an email address.

Yes, email is an imperfect tool. But it is also the lingua franca of business communication. It is decentralized and asynchronous, and its support of rich long-form content is simply better suited for certain types of jobs. Even if you disagree with all that and have vowed never to use email again, odds are that you will still be forced to because your boss uses email…or your customers…or your old friend Jerry.

Gmail, Outlook 365 and a number of new email clients recognize this inherent gravity of email and have made efforts to integrate with other tools and platforms, but they face constraints: lock-in with proprietary email clients, limited integrations and deep technical expertise requirements to integrate / modify any new or custom systems.

With MailBots, we’re approaching email productivity from another angle: bots.

A Different Kind of Bot

Now, what about all of the other bot platforms — they support email too, right? Some do, yes, but their email integration is usually an afterthought. The best bot platforms focus on their primary use-case — Slack, Facebook Messenger, Telegram and other classic “chatbot” platforms.

Some consider bots and “chatbots” synonymous. Thankfully this is not the case. Few things would be more annoying than a “chatty” email bot that incessantly clutters your inbox. A “bot” does not necessarily imply a conversational UI, instant replies or annoying levels of chattiness.

A bot created on the MailBots platform is usually a single-purpose email recipient that helps you get something done without leaving your inbox — things like entering data into a CRM, or offering a one-click link to order flowers for someone’s birthday. A MailBot doesn’t have to be chatty or even respond when you tell it to do something. A MailBot streamlines your inbox and reduces context switching by helping you get things done in one place.

Simply put, MailBots is a bot platform optimized exclusively for email, embracing all of its annoyances, challenges — and opportunities.

Our Platform Features

Creating a MailBot and managing it is fun and easy. Here are a few highlights:

When setting up your bot, you can select your own email bot sub-domain. Using our pizza ordering bot as an example, this could be something like: Routing based on the subdomain domain allows for something special before the @ symbol: the bot command.

Email Commands
Anything before the @ symbol is an explicit command to your bot. FollowUpThen popularized the “email command” (e.g.,, follows up in three days, next week and 9:52 p.m. respectively), but only scratched the surface. MailBots lets bot creators accept any command before the @ symbol. For example:,, Email commands are made vastly more awesome and near-instantaneous by your email client’s autocomplete feature.

Natural Language Processing
MailBots can integrate with natural language processing systems like to allow for human-like interaction and understanding. Natural language intents are mapped to commands. This allows bot creators the freedom to expose a friendly personal assistant context alongside the more explicit and efficient email-command UI (that geeks like us tend to like more).

Quick-Action Buttons
MailBots offer one-click email-based buttons that issue bot actions without requiring a verbose text response or even leaving the inbox.

Perfect Timing
Unlike a chatbot, email is usually asynchronous. A MailBot interaction may begin with a single command then days, weeks or months later, follow up at the perfect moment with the everything needed to get something done. MailBots was created specifically for these long cycle-time interactions. It even exposes a FollowUpThen’esque parser so any MailBot can accept commands like or

Tasks, Not Conversations
Chatbots have conversations. MailBots accomplish “tasks” and may, optionally, converse in reference to a task. A MailBot “task” is like an email with to-do list features such as scheduling, editing and completion status. They can store meta information about the conversation or references to an external resource (like contact in a CRM).

In the context of a traditional chatbot, a “task” is like a chatbot conversation that you can cryogenically freeze, edit and then revive days, months or years later.

Users can search, view, edit their pending (cryogenically frozen) tasks on

When designing the web UI, we specifically made a point of mirroring an email client. This not only provides a consistent user experience, but also greatly reduces the effort in building a MailBot since developers only need to think about one email-based UI

MailBot settings are managed on, providing users with a consistent experience during setup and when authorizing external connections (CRM, Calendar, etc).

Bot development is the subject of a future post, but here is a preview of how the above “Confirmation Emails” setting is defined:

name: "confirmation_emails",
title: "Confirmation Emails",
description: "Receive confirmation emails with each action",
defaultValue: true


Open Source Kit
The brains and logic of your bot are yours to host and develop in any environment you would like. The bot setup process provides a working instance of our Node.js Starter kit on Glitch within a few seconds, but the libraries are available under a permissive MIT license. The core API sends and receives JSON-based webhooks, allowing for development on any platform. This allows you to keep API keys and connections private, integrate proprietary code and use familiar development tools.

More to come…

MailBots has been a long time coming —about a year and half now!

We would like to thank our amazing FollowUpThen users for the inspiration behind the MailBots platform. Since founding FollowUpThen in 2010, we have seen email used not only as a to-do list but also as a CRM, project management system, shopping list, personal database, motivational tool, tutor, relationship coach and more. On more than one occasion, users have thanked us for saving their jobs. And their marriages.

We never considered how much could be done with email until connecting with so many people who genuinely love to email — yes, they are out there! — and who use it in awesomely creative ways to boost their productivity.

Thank also to the core group of developers who have given us feedback so far, and to our Y Combinator advisors, batch-mates and friends for helping to shape the direction of the company.

If you would like early access to MailBots, fill out our developer survey. If you would rather sign up for the occasional email update, that’s great too. Just enter your email at

We can’t wait to see what you create!



Reilly Sweetland

Founder of Gopher (YC S17), FollowUpThen, Internet Simplicity (acq 2016), TypeRoom. Productivity enthusiast, autodidact, hacker, nutritionist, husband, dad.