Redmine

Hello community,

I am trying to get e-mail notifications work with Redmine 5.0.2.stable and Microsoft Exchange 2013 Mail Server.

I followed this instructions (https://www.redmine.org/projects/redmine/wiki/howto_configure_redmine_to_mail_to_ms_exchange_server) for the configuration and the main lines of my configuration.yml just looks like this:

production:
  delivery_method: :smtp
  smtp_settings:
    address: mail.domain.com
    port: 25

I needed a SMTP program so I installed sendmail first and got an SSL error. Then I uninstalled it and installed postfix instead but I got the same SSL error which is:

"An error occurred while sending mail (SSL_connect returned=1 errno=0 state=error: unexpected eof while reading)" 

This error appears when I click on send test mail on the e-mail notification tab under the main configuration.

I checked both apache and redmine logs but I didn't find useful information to understand what's happening.

Could you please help me with this problem?

This is some of the information of my environment:

Operating System: Red Hat Enterprise Linux 9

Redmine Environment:
Redmine version 5.0.2.stable
Ruby version 3.0.4-p208 (2022-04-12) [x86_64-linux]
Rails version 6.1.6
Environment production
Database adapter Mysql2
Mailer queue ActiveJob::QueueAdapters::AsyncAdapter
Mailer delivery smtp
Redmine settings:
Redmine theme Default
SCM:
Subversion 1.14.1
Mercurial 6.1.4
Git 2.31.1
Filesystem
Redmine plugins:
no plugin installed

Output of:

ruby -ropenssl -e 'puts OpenSSL::OPENSSL_VERSION'

-> OpenSSL 3.0.1 14 Dec 2021

ruby -ropenssl -e 'puts OpenSSL::SSL::SSLContext::DEFAULT_PARAMS'

-> {:min_version=>769, :verify_mode=>1, :verify_hostname=>true, :options=>2147614800}