Outbound SMTP Policy
EDBB keeps TCP port 25 open so you can run your own mail services. To protect shared IP reputation, outbound traffic is rate-limited to 8 packets per second with an initial burst of 16 pps.
Why We Rate-Limit Port 25
🛡️ IP Reputation
Throttling prevents sudden spam bursts that could land shared IP ranges on blocklists.
⚖️ Fair Usage
Keeps one VPS from monopolizing outbound SMTP bandwidth.
🚫 Abuse Deterrence
Makes the platform less attractive for spammers while staying practical for legitimate email.
📅 Consistent Policy
Applies to every VPS created after 24 February 2025. The limit is not adjustable per account.
What This Means for You
- Transactional email, server alerts, and admin notifications operate normally.
- Bulk campaigns or newsletters should use dedicated providers (SendGrid, Mailgun, Amazon SES, etc.).
- Exceeding the limit will slow delivery but won’t block single messages outright.
- EDBB enforces a strict no-spam policy—verified abuse leads to suspension without refund.
Best Practices
- Configure SPF, DKIM, and DMARC to improve deliverability.
- Monitor mail queues and bounce reports; most issues stem from application misconfiguration rather than the rate limit.
- Keep abuse contacts current in WHOIS/RDAP so you can respond quickly to complaints.
- For high-volume sending, integrate with a reputable SMTP relay service.