Changes to email sending (outgoing port 25/TCP) from our MojoServers Print

To protect our infrastructure, maintain a positive sender reputation, and ensure reliable email delivery for all our users, we will be blocking outgoing traffic on port 25/TCP on our MojoServers. This change is necessary due to the increasing prevalence of spam and abuse originating from compromised servers using this port.

What is Port 25, and Why is This Happening?

Port 25 is the standard port used by the Simple Mail Transfer Protocol (SMTP) for sending emails. Unfortunately, it's also a frequent target for spammers and malicious actors. By blocking outgoing port 25, we significantly reduce the risk of our servers being used to send unwanted or harmful emails. This protects our collective online reputation and helps ensure that legitimate emails you send are not blocked by recipient servers.

What are the Recommended Solutions?

1. Use a Dedicated Email Service Provider (ESP): This is the most recommended solution. ESPs like SendGrid, Mailgun, Amazon SES, Postmark, and others provide robust email delivery infrastructure, handle bounce management, spam filtering, and authentication (SPF, DKIM, DMARC). They also help maintain a good sender reputation.
2. Use Port 587 for Submission: You can continue sending email by configuring your applications to use port 587/TCP with appropriate authentication (username and password) to your external email server or provider. This is the standard port for secure email submission.
3. Submit a Support Request (For Exceptional Cases): If you have a legitimate and compelling need to send email directly from our MojoServers (and cannot use the above options), please send it via our support ticketing system. Requests will be reviewed on a case-by-case basis, and approval is not guaranteed. You might be requested to provide information about your use case and/or demonstrate that you have implemented appropriate security measures.

Effective Date: Thursday, October 23rd, 2025.

We appreciate your understanding as we take these necessary steps to improve the security and reliability of our services.