PAS-C01 Operations and Maintenance Practice Question
An SAP system fails to send emails via SAPconnect using SMTP. The EC2 instance has a public IP and the security group allows outbound traffic on port 25. The SMTP server is an on-premises relay. What is the most likely reason for the failure?
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
✓
AWS blocks outbound traffic on port 25 by default for EC2 instances.
The most likely reason is that AWS blocks outbound traffic on port 25 by default for EC2 instances to prevent spam. This restriction applies even if the security group allows outbound port 25 traffic. Option A is incorrect because the security group allows outbound traffic on port 25, but the default AWS block overrides it. Option C is incorrect because the instance has a public IP. Option D is incorrect because the route table is not the issue; the instance has a public IP and can reach the internet, but port 25 is blocked at the AWS level.
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 security group does not allow outbound traffic on port 25.
Why it's wrong here
The security group allows outbound on port 25.
- ✓
AWS blocks outbound traffic on port 25 by default for EC2 instances.
Why this is correct
AWS restricts port 25 outbound; you need to request removal or use a different port.
- ✗
The EC2 instance does not have a public IP address associated.
Why it's wrong here
The instance has a public IP as stated.
- ✗
The route table does not have a default route to an internet gateway.
Why it's wrong here
With a public IP, a default route to IGW is assumed.
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JA
Written by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
This PAS-C01 practice question is part of Courseiva's free Amazon Web Services 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 PAS-C01 exam.