How to fix SMTP Transaction Time timeouts in cPanel?

Updated: 28 September 2026 · Applies to: cPanel & WHM 138 (WHM, root access)

To slow down spammers, cPanel's Exim can pause before answering hosts it does not trust. Legitimate senders on slow or strict systems sometimes time out because of this.

Steps

1. Log in to WHM as root (https://your-server:2087).
2. Open Service Configuration › Exim Configuration Manager.
3. On the Basic Editor tab, find Introduce a delay into the SMTP transaction for unknown hosts and messages detected as spam.
4. Set it to Off and click Save.

Exim restarts with the new setting. Other spam protections stay in place.

Tip: If only one sender has problems, add their mail server to a trusted list instead (for example Trusted SMTP IP addresses in the Exim Configuration Manager), so the delay stays on for everyone else.