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.
Table of Contents
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?
- Spam Prevention: Prevents compromised servers from sending spam
- IP Reputation Protection: Prevents REXE IP ranges from being blacklisted
- Customer Protection: One customer's spam activity doesn't affect others
- Legal Compliance: Compliance with anti-spam regulations
Requesting Mail Sending Permission
- Log in to REXE support panel (my.rexe.tr)
- Create a new support ticket
- 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
| Service | Free Plan | Description |
|---|---|---|
| SendGrid | 100 emails/day | Transactional and marketing emails |
| Mailgun | 5,000 emails/month | API-based email sending |
| Amazon SES | 62,000 emails/month | AWS ecosystem integration |
| Brevo | 300 emails/day | Easy 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
Related Articles
SSH Connection Problem: Can't Connect to Server
SSH connection troubleshooting guide: Path.net firewall rules, Default Block, creating a filter rule for SSH port, and step-by-step troubleshooting.
RDP Connection Problem: Can't Connect to Windows Server
RDP connection troubleshooting guide: Path.net firewall rules, Default Block, creating a filter rule for RDP port, and step-by-step troubleshooting.
How to Run an MTR Test and Submit Results to Support
Guide to running MTR network tests with WinMTR and Linux MTR, creating ICMP filter rules, and submitting results to support. Diagnose packet loss and latency.