• What's new

Weekly Product Update: Better Handling Of Non-ASCII Characters In Routes

Mailgun Team
5 min read

This week, we’ve rolled out an enhancement, ok, we’ve fixed a bug, in our email parsing API, which is part of our incoming email handling system called Routes. Routes are one of our most popular features because it allows you to handle all those replies to your marketing and transactional emails. Some customers also use this incoming email handling feature to do cool things like let their customers use email to create tasks in a project management app or take part in an online discussion board via email.

Which leads us to better support for non-ASCII characters

When a user asks Mailgun to parse their incoming emails and POST to their app via HTTP, we parse quotations, signatures, and attachments and then post them to a webhook. If a message doesn’t have an HTML part (e.g. it was sent as plain text only) we still try to build an html part from the provided text part and post it as a stripped-html parameter (we also create the stripped-text part when an HTML-only email is received).

Recently a bug was found for this particular use case if the text part included non-ASCII characters. When this happened, they were corrupted in the stripped-html, so for example, “日本語” was transformed into “日本語”. Now the bug is fixed and Mailgun properly creates proper html from text, even with non-ASCII characters.

Tell me more about Routes

This seems like a good a time as any to go over what Routes enable because they are really powerful. Routes allow you to set up a series of rules on how to handle incoming messages. Specifically:

  • Which messages to act on (e.g. messages from a particular person or with a particular subject or even all messages)

  • What you want to do with those messages (e.g. forward it to another email address or POST it to your app)

When you elect to post the message to your app, Mailgun will either send you the entire unparsed MIME message (if that’s your thing) or parse it for you and POST the parsed parameters. In both cases, we’ll transcode the message to UTF-8 because we love our customers.

Below is a list of the parsed parameters that we will POST to your app when using Routes.

Accepting incoming webhooks

You’ll need to set up your app to receive the parsed parameters. Here is a little flask app that shows you the basics so if you aren’t already, you can start using Routes to handle incoming messages!

from flask import Flask from flask import request app = Flask(__name__) @app.route('/mailgun-tracking', methods=['GET', 'POST']) def tracking(): # access some of the email parsed values: request.form['recipient'] request.form['from'] request.form['subject'] # extended parameters request.form['Message-Id'] request.form['message-headers'] request.form['timestamp'] request.form['body-plain'] request.form['stripped-html'] request.form['stripped-text'] request.form['stripped-signature'] return "Ok" if __name__ == '__main__': app.run(host='', port=100, debug=True)

And finally our new blog…

If you’re a long time Mailgun reader, you’ll notice that we have a new blog. Some of the new things we think you’ll like are:

  • It’s responsive so you can read it easily on any device

  • You can subscribe now to get updates when a new blog is posted (and absolutely no other emails you don’t want)

  • Each post has related docs so if you read a post about a customer using Mailgun Routes to do something cool, you’ll be able to find the docs most closely related to that topic directly from the post.

We hope you like the new blog. Let us know what you think.


Learn about our Deliverability Services

Looking to send a high volume of emails? Our email experts can supercharge your email performance. See how we've helped companies like Lyft, Shopify, Github increase their email delivery rates to an average of 97%.

Learn More

Last updated on August 28, 2020

  • Related posts
  • Recent posts
  • Top posts
View all

Always be in the know and grab free email resources!

No spam, ever. Only musings and writings from the Mailgun team.

By sending this form, I agree that Mailgun may contact me and process my data in accordance with its Privacy Policy.

sign up
It's easy to get started. And it's free.
See what you can accomplish with the world's best email delivery platform.
Sign up for Free