localhost로 전송된 이메일은 sSMTP 레코드를 사용합니까?

sSMTP가 localhost에서 메일을 보내는 데 적합하지 않다고 생각합니까?

nicholas@mordor:~$ 
nicholas@mordor:~$ sudo cat /etc/ssmtp/ssmtp.conf
#
# Config file for sSMTP sendmail
#
# The person who gets all mail for userids < 1000
# Make this empty to disable rewriting.
root=postmaster

# The place where the mail goes. The actual machine name is required no 
# MX records are consulted. Commonly mailhosts are named mail.domain.com
mailhub=mail

# Where will the mail seem to come from?
#rewriteDomain=

# The full hostname
hostname=mordor.saundersconsulting.tech

# Are users allowed to set their own From: address?
# YES - Allow the user to specify their own From: address
# NO - Use the system generated From: address
#FromLineOverride=YES
nicholas@mordor:~$ 
nicholas@mordor:~$ sudo cat /etc/ssmtp/revaliases
# sSMTP aliases
# 
# Format:   local_account:outgoing_address:mailhub
#
# Example: root:[email protected]:mailhub.your.domain[:port]
# where [:port] is an optional port number that defaults to 25.
nicholas@mordor:~$ 
nicholas@mordor:~$ swaks --to [email protected] --from [email protected] --server mordor.saundersconsulting.tech
=== Trying mordor.saundersconsulting.tech:25...
*** Error connecting to mordor.saundersconsulting.tech:25:
***     IO::Socket::INET6: connect: Connection refused
nicholas@mordor:~$ 
nicholas@mordor:~$ hostname
mordor.saundersconsulting.tech
nicholas@mordor:~$ 
nicholas@mordor:~$ lsb_release -a
No LSB modules are available.
Distributor ID: Ubuntu
Description:    Ubuntu 23.10
Release:    23.10
Codename:   mantic
nicholas@mordor:~$ 

이전에 시도한 mail.log 및 mail.err의 gmail 외에는 언급된 것이 없습니다. 내가 아는 한 sSMTP는 이메일만 중계합니다.

주목할만한 결과:

nicholas@mordor:~$ 
nicholas@mordor:~$ ssmtp [email protected]
subject:ping

ssmtp: Cannot open mail:25
nicholas@mordor:~$ 

sSMTP가 포트 25를 열 수 없습니까?