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Can't Send Email from Server: Causes and Solutions

Why outbound email is blocked by default on REXE servers, how to request mail sending permission, and alternative external SMTP solutions like SendGrid.

Read time: 5 min Troubleshooting
email problemsmtpport 25outbound mail blocksendgridspam preventiontroubleshooting
Author
REXE Teknoloji Network & Security Team
Editor
REXE Teknoloji Technical Editorial
First published
Last updated

Introduction

On REXE Technology servers, outbound mail traffic is blocked by default. This is a security policy to prevent spam sending and protect our IP addresses from being blacklisted.

This block only affects outbound mail traffic (SMTP — ports 25, 465, 587). Incoming mail traffic is not affected.

Why Is Mail Traffic Blocked?

  1. Spam Prevention: Prevents compromised servers from sending spam
  2. IP Reputation Protection: Prevents REXE IP ranges from being blacklisted
  3. Customer Protection: One customer's spam activity doesn't affect others
  4. Legal Compliance: Compliance with anti-spam regulations

Requesting Mail Sending Permission

  1. Log in to REXE support panel (my.rexe.tr)
  2. Create a new support ticket
  3. Include the following information:
Subject: Mail Sending Permission Request

Server IP: [Your server IP]
Purpose: [Explain your mail sending purpose]
Mail Server Software: [Postfix, Sendmail, External SMTP, etc.]
Estimated Daily Volume: [Approximate daily email count]

Mail sending permission is subject to review. Spam or bulk unsolicited email sending is strictly prohibited.

Alternative: External SMTP Service

ServiceFree PlanDescription
SendGrid100 emails/dayTransactional and marketing emails
Mailgun5,000 emails/monthAPI-based email sending
Amazon SES62,000 emails/monthAWS ecosystem integration
Brevo300 emails/dayEasy setup

External SMTP services generally provide higher deliverability rates, independent of your server's IP reputation.

After Mail Sending Is Enabled

  • Set up SPF record in DNS
  • Configure DKIM for email signing
  • Set DMARC policy
  • Request Reverse DNS (PTR) record from support

Frequently Asked Questions

Why can't I send email from my server?

Outbound mail traffic (SMTP ports) is blocked by default on REXE servers. Create a support ticket to request permission.

How do I get mail sending permission?

Create a support ticket at my.rexe.tr, specify your server IP and mail usage purpose.

Can I send email immediately without waiting for permission?

Yes, you can use external SMTP services like SendGrid, Mailgun, or Amazon SES immediately. These services offer free plans and work independently of your server's IP reputation.

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