hardMultiple ChoiceObjective-mapped
350-701 Practice Question: While troubleshooting an issue where Cisco ESA…
While troubleshooting an issue where Cisco ESA occasionally fails to process inbound messages, the administrator checks the listener settings and sees that the 'Pool of listeners' option is configured. The mail logs show 'Connection refused' errors during peak hours. What is the most likely cause?
⚠ Common exam trap
Cisco often tests the distinction between a stopped service (which causes persistent failures) and a resource-exhausted pool (which causes intermittent failures during high load), leading candidates to mistakenly choose 'listener service is stopped' when the logs show 'Connection refused' only at peak times.
Answer choices
Why each option matters
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
Listener pool has too few listeners or the pool is misconfigured
The 'Connection refused' error during peak hours indicates that the Cisco ESA's listener service is actively rejecting new SMTP connections because the configured listener pool has reached its maximum capacity. The 'Pool of listeners' option defines a set of listener processes that handle inbound mail; if the pool size is too small for the traffic volume, new connections are refused. This is a resource exhaustion issue specific to the listener pool, not a service outage or external blocking.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
The listener service is stopped
Why it's wrong here
If stopped, all connections would be refused, not just during peak.
- ✓
Listener pool has too few listeners or the pool is misconfigured
Why this is correct
A pool of listeners uses the same IP:port and can become exhausted if too many simultaneous connections.
- ✗
The sender's IP is blacklisted
Why it's wrong here
Blacklisting results in a rejection message, not 'Connection refused'.
- ✗
DNS resolution failure for the sending MTA
Why it's wrong here
DNS failure would typically cause a deferral, not a connection refused error.
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JA
Written by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
This 350-701 practice question is part of Courseiva's free Cisco certification practice question bank. Courseiva provides original exam-style practice questions with explanations, topic-based practice, mock exams, readiness tracking, and study analytics to help learners prepare for the 350-701 exam.