SK0-005 · Question #587
An administrator runs a port scan and finds the following port list: Which of the following changes should the administrator make to only allow encrypted email ports? (Choose two.)
The correct answer is A. Close port 25. F. Open port 993. To allow only encrypted email, the administrator should close the unencrypted SMTP port (25) and open the dedicated encrypted IMAP port (993).
Question
An administrator runs a port scan and finds the following port list:
Which of the following changes should the administrator make to only allow encrypted email ports? (Choose two.)
Options
- AClose port 25.
- BOpen port 80.
- COpen port 143.
- DOpen port 443.
- EClose port 587.
- FOpen port 993.
How the community answered
(24 responses)- A75% (18)
- B4% (1)
- D8% (2)
- E13% (3)
Why each option
To allow only encrypted email, the administrator should close the unencrypted SMTP port (25) and open the dedicated encrypted IMAP port (993).
Port 25 is typically used for unencrypted SMTP (Simple Mail Transfer Protocol) server-to-server communication. To only allow encrypted email, this port should be closed or restricted to prevent unencrypted mail transfer.
Port 80 is for unencrypted HTTP web traffic, which is unrelated to email and does not need to be open for encrypted email.
Port 143 is for unencrypted IMAP (Internet Message Access Protocol), and opening it would allow unencrypted email access, contrary to the requirement for only encrypted email.
Port 443 is for HTTPS (encrypted web traffic) and while encrypted, it is not an email port. Opening it does not specifically relate to allowing encrypted email.
Port 587 is for SMTP Message Submission, which commonly uses STARTTLS for opportunistic encryption. Closing it would prevent many legitimate email clients from sending encrypted mail, which contradicts the goal of allowing encrypted email.
Port 993 is the standard port for IMAP over SSL/TLS (IMAPS), which is used for securely retrieving email. To allow encrypted email, this port must be open for clients to access their mail securely.
Concept tested: Standard encrypted email ports
Source: https://learn.microsoft.com/en-us/exchange/architecture/mail-flow/ports-and-protocols
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