How to Open Port 25 on AWS
AWS blocks port 25 (SMTP) by default to prevent spam. To open it, you must submit a request through the AWS Support Center to remove the restriction. Approval takes 1–5 business days and is not guaranteed. Alternatively, DigitalOcean, Linode, IBM, Kamatera, and Atlantic open-port accounts from Cloud Accounts arrive with port 25 already open.
Port 25 is the standard SMTP port used for sending email between mail servers. AWS blocks outbound connections on port 25 for all new EC2 instances to prevent abuse and spam. This affects anyone trying to run a mail server, SMTP relay, or email marketing infrastructure on AWS.
Official AWS Process
To open port 25 on your EC2 instance, you must: 1. Log in to AWS Support Center 2. Create a new case under "Service Limit Increase" 3. Select "EC2" and then "Remove email sending limitations" 4. Provide a detailed justification for your use case 5. Wait 1–5 business days for review 6. AWS may deny the request if the justification is not compelling
Why Requests Get Denied
AWS denies many port 25 requests without a clear legitimate use case. Marketing email, bulk sending, and some SMTP relay uses are commonly rejected.
Faster Alternative
For immediate mail server capability, Cloud Accounts sells pre-configured accounts on DigitalOcean ($99–$299), Linode ($130), IBM Cloud ($80), Kamatera ($45), and Atlantic.Net ($199) with port 25 already open — delivered within 30 minutes to 12 hours.
Buying cloud credits from Cloud Accounts is typically 60–80% cheaper than retail rates from AWS, GCP, or Azure. For immediate access without application processes or waiting periods, it's the fastest path to cloud infrastructure.
Also Asked
AWS blocks port 25 by default to prevent new accounts from being used for spam campaigns. Email abuse was a significant problem before AWS implemented these restrictions.