Preparation

mailsort is a Python module to automate the filtering of emails on any IMAP mail server. It assigns emails to folders based on their similarity to other emails already assigned to the same folder.

Many people struggle with the increasing email volume leading to hundreds of unread emails. As the capabilities of even the best search engine are limited when it comes to large numbers of emails, the only way to keep an overview is filtering emails into folders. The manual process of filtering emails into folders is tedious, still most people are too lazy to create email filters and keep their email filters up to date. Finally, in the age of mobile computing when most people access their emails from their smartphone, the challenge of sorting emails is more relevant than ever.

The solution to this challenge is to automatically filter emails depending on their similarity to existing emails in a given folder. This solution was already proposed in a couple of research papers ranging from the filtering of spam emails E.G. Dada et al. to the specific case of sorting emails into folders R. Bekkerman et al.. Even a couple of opensource prototypes are available like ml-email-clustering and emailinsight.

mailsort takes this idea and applies it to any mail server reachable over plain IMAP - so it works equally well with a self-hosted mail server, a company mailbox, or any provider that is not Google Mail (for Google Mail itself, see gmailsorter). Before using mailsort you first have to sort your emails manually. This step is necessary for mailsort to learn your preferences.

Sort your emails

While the ordering of information is generally a very personal topic, with no one solution which fits anybody. Still some general considerations can be helpful to sort your emails:

• How many emails go into one email folder? And how many email folders do you need? It is typically suggested to start with around ten email folders with each folder containing more or less the same amount of emails.

• To sort your email folders you can start their names with a number, this enforces the right order of email folders independent of the email client.

• For mailsort to be able to learn how to treat any kind of incoming email, it makes sense to have an email folder for emails you plan to delete. These could be newsletters, spam messages or other unrelated emails.

Before you activate mailsort it is essential that you clean up your whole inbox and sort each email into a folder. Do not delete the emails even if they are irrelevant. To sort your emails you can use your favorite email client, or alternatively you can log in to your mail provider’s web interface and sort your emails there.

Configure your email account

For mailsort to connect to your mail account, it needs an IMAP server hostname, port, username and password.

Enable IMAP access

Most mail providers disable IMAP access by default and require you to explicitly enable it in your account settings - check your provider’s documentation for the exact steps (searching for “ enable IMAP” is usually the fastest way to find them).

Use an app password instead of your account password

If your mail provider supports two-factor authentication, it typically requires you to create a separate app password for IMAP access rather than using your regular account password. This has the added benefit that the app password can be revoked independently at any time, without having to change your main account password. mailsort never persists your password anywhere - it is only used to log in to the IMAP server for the duration of a connection.

Create one separate folder as inbox for mailsort

To minimize the interruption of incoming emails, it is recommended to create a new inbox folder, for example named MailSortInbox. You then configure a filter in your mail account (or your existing email client) to redirect new incoming emails into this folder. Emails in the MailSortInbox folder are then periodically sorted using mailsort, typically every five minutes - see Configuration for how to schedule this.