notify-host-mail: Does not support STARTTLS SMTP servers

[laison007]

This issue respects the following points:

• This is a bug, not a question or a setup/configuration issue.
• This issue is not already reported on Github (I've searched it).
• I use the latest release of the Monitoring Plugins (https://github.com/Linuxfabrik/monitoring-plugins/releases).
• I agree to follow Monitoring Plugins's Code of Conduct.

Which variant of the Monitoring Plugins do you use?

• .rpm/.deb package from repo.linuxfabrik.ch
• Compiled for Linux (.tar/.zip from download.linuxfabrik.ch)
• Compiled for Windows (from download.linuxfabrik.ch)
• Source Code from GitHub

Bug description

Hello friends.

I am trying to configure notifications for alarms, to be sent by mail to an address created for that purpose, in Office 365 and I have found that the plugin is not prepared for SMTP servers using STARTTLS, I have checked in the Python documentation that in the library used if STARTTLS is supported, but the script or plugin does not provide for this option.

I offer to test but my Python knowledge is limited.

Best regards.

Here is the error I get when running the notify-host-mail plugin

root@Icinga-Server:/usr/lib64/nagios/plugins# ./notify-host-mail --datetime 03/04/2023-17:00 --host-displayname Icinga-Server --host-state Down --mail-recipient @.com --mail-sender @.com --short
Traceback (most recent call last):
File "/usr/lib64/nagios/plugins/./notify-host-mail", line 497, in 'module'
main()
File "/usr/lib64/nagios/plugins/./notify-host-mail", line 491, in main
s.send_message(mail_msg)
File "/usr/lib/python3.11/smtplib.py", line 986, in send_message
return self.sendmail(from_addr, to_addrs, flatmsg, mail_options,
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/usr/lib/python3.11/smtplib.py", line 887, in sendmail
raise SMTPSenderRefused(code, resp, from_addr)
smtplib.SMTPSenderRefused: (451, b'5.7.3 STARTTLS is required to send mail [P**********.F*****.PROD.OUTLOOK.COM 2024-04-04T07:01:48.396Z ]', '@****.com')

Link to Python lib smtplib:

https://docs.python.org/3/library/smtplib.html

Steps to reproduce - Plugin call

notify-host-mail --datetime 03/04/2023-17:00 --host-displayname Icinga-Server --host-state Down --mail-recipient @.com --mail-sender @.com --short

Steps to reproduce - Data

No response

Environment

Linux Icinga-Server 6.1.0-18-amd64 #1 SMP PREEMPT_DYNAMIC Debian 6.1.76-1 (2024-02-01) x86_64 GNU/Linux

Plugin Version

notify-host-mail: v2023112901 by Linuxfabrik GmbH, Zurich/Switzerland

Python version

Python 3.11.2

List of Python modules

No response

Additional Information

No response