Problems with Transactional Emails from MailGun in Outlook and Hotmail Being Flagged as Spam

Understanding Delivery Challenges for Transactional Emails

Transactional emails are essential for keeping lines of communication open with clients, particularly when providing updates and confirmations about their transactions. But when recipients begin to receive these emails in their spam boxes, it can cause serious communication problems and discontent. This issue is especially noticeable when utilizing email services such as MailGun, which works well on most platforms but has issues with other providers, such as Hotmail and Outlook.

Emails still end up in the spam folder even after properly configuring DNS entries like SPF, DKIM, CNAME, MX, and DMARC; this suggests a more serious problem with how these services interpret and filter incoming emails. Even after attempting various email formats and acquiring new domains, the problem still exists, indicating that a more comprehensive approach to solving it may be necessary than merely making technical changes. This introduction examines the ongoing challenges that MailGun has in guaranteeing the delivery of transactional emails, particularly to users of Outlook and Hotmail.

Examining MailGun's Automatic DNS and Email Configuration

The scripts provided address two major facets of email deliverability for transactional emails using MailGun, especially targeting platforms like Outlook and Hotmail where emails frequently land in the spam folder. The first script, utilizing the Python dnspython library, focuses on updating DNS records to ensure that they are correctly configured to improve email deliverability. This involves setting up SPF (Sender Policy Framework), DKIM (DomainKeys Identified Mail), and DMARC (Domain-based Message Authentication, Reporting & Conformance) records. These DNS records are crucial for mail servers to authenticate the emails originating from your domain, significantly reducing the chances of them being marked as spam. The script dynamically updates these records using authenticated DNS updates, which are critical in maintaining the integrity and trustworthiness of the emails being sent.

The second script makes use of the Flask framework and Python to build a basic backend service that makes use of MailGun's API to deliver emails. With the help of this script, a working online application may be used to send emails through an endpoint that accepts POST requests containing the recipient, topic, and email body, among other necessary data. Through the usage of this script, customers may effortlessly handle transactional emails by integrating MailGun's email sending features straight into their websites or applications. This backend configuration also shows how applications can communicate with other APIs to expand their capabilities. For example, it can automate emails that confirm orders straight from an e-commerce platform, improving customer service and operational effectiveness.

import dns.resolver
import dns.update
import dns.query
import dns.tsigkeyring
import dns.zone
# Define the domain and DNS server
domain = 'example.com'
dns_server = 'ns.example.com'
keyring = dns.tsigkeyring.from_text({'keyname': 'base64==', 'keyalgorithm': dns.tsig.HMAC_SHA256})
# Update DNS records for SPF, DKIM, and DMARC
update = dns.update.Update(domain, keyring=keyring)
update.replace('example._domainkey', 3600, 'TXT', 'v=DKIM1; k=rsa; p=your_public_key_here')
update.replace('@', 3600, 'TXT', 'v=spf1 include:mailgun.org ~all')
update.replace('_dmarc', 3600, 'TXT', 'v=DMARC1; p=none; rua=mailto:dmarc-reports@example.com')
response = dns.query.tcp(update, dns_server)
print("DNS Update Response:", response)

from flask import Flask, request, jsonify
import requests
# Initialize the Flask application
app = Flask(__name__)
# Mailgun settings
MAILGUN_API_KEY = 'your-mailgun-api-key'
MAILGUN_DOMAIN = 'your-mailgun-domain'
def send_email(recipient, subject, text):
    return requests.post(
        f"https://api.mailgun.net/v3/{MAILGUN_DOMAIN}/messages",
        auth=("api", MAILGUN_API_KEY),
        data={"from": "Mailgun Sandbox <mailgun@{MAILGUN_DOMAIN}>",
              "to": recipient,
              "subject": subject,
              "text": text})
@app.route('/send', methods=['POST'])
def handle_send_email():
    email_info = request.json
    result = send_email(email_info['recipient'], email_info['subject'], email_info['text'])
    return jsonify(status=result.status_code, data=result.json())
if __name__ == '__main__':
    app.run(debug=True, port=5000)

Improving Email Deliverability With Strategic Content Administration

It takes more than just setting up DNS correctly to improve email deliverability, especially for transactional emails that frequently wind up in spam folders on services like Outlook and Hotmail. One important factor is the type and caliber of the content in the emails themselves. The wording used in transactional emails must not set off spam filters. Overly promotional language, an overabundance of capital letters, and an excessive number of links are common triggers. Deliverability can be enhanced by concentrating on utilizing language that is clear, succinct, and professional. It is also beneficial to personalize the emails to not only engage the recipient more effectively but also to avoid the appearance of bulk, generic messaging, which is a common characteristic of spam.

The engagement rate of emails sent is another important factor. Mail servers monitor how recipients respond to new emails. The sender's reputation may suffer if a sizable portion of emails are routinely ignored, deleted, or classified as spam by receivers. This may raise the possibility that emails will be filtered into the spam folder. Engagement rates can be considerably raised by regularly purging inactive members from the email list and ensuring that emails load quickly and are available on mobile devices. To put these techniques into practice, transactional emails must be carefully designed and distributed to ensure that the recipients find them interesting and useful.