LM5 can't send an email

[Fahd]

Hi, 

I'm using this script in all of our projects to send a backup each month.
One of the LM5 can't send it anymore and  got this in the logs

* string: connection refused 
* nil
* string: Send Mail

NB: LM5 is connected to the ethernet.

What could be the issue?

Code:

--***************************************************************--
--*** For FW spaceLYnk 1.2.1 and FW homeLYnk 1.5.1 or higher ****--
--***************************************************************--
--** Email backup as attachment created by Erwin van der Zwart **--
--***************************************************************--
--********************* Start of parameters *********************--
--***************************************************************--

--Gmail (smtp) username !IMPORTANT!
user = 'xxxx'

--Gmail (smtp) password !IMPORTANT!
password = 'xxxx'

--Sender for e-mail
from = '<xxxx>'
alias_from = 'From me'

--Recipient for e-mail
to = '<xxxx>'
alias_to = 'To you'

--Subject for e-mail
subjectpart1 = 'Back-up file'
subjectpart2 = 'xxx'

--Message on bottom of email (will only be showed when client don't understand attachment)
epilogue = 'End of message'

--***********************************************************--
--******************** End of parameters ********************--
--***********************************************************--
--********** DON'T CHANGE ANYTHING UNDER THIS LINE **********--
--***********************************************************--

--Create table to include mail settings
local settings = {
    from = from,
    rcpt = to,
    user = user,
    password = password,
    server = 'smtp.office365.com',
    port = 587,
    secure = 'tlsv1_2',
        starttls = true,
}

--Create attachment
src = 'backup-' .. os.date('%Y.%m.%d') .. '.tar.gz'
dst = '/home/ftp/' .. src

-- prepare files for backup
os.execute('sh /lib/genohm-scada/web/general/backup.sh')

-- create cleanup archive
os.execute('cd /lib/genohm-scada/storage && tar -c -z -f ' .. dst .. ' ./')

--Create subject
subject = subjectpart1 .. ": " .. src .. " " .. subjectpart2

--Load required modules to send email with attachment
local smtp = require("socket.smtp")
local mime = require("mime")
local ltn12 = require("ltn12")

--Create e-mail header
settings.source = smtp.message{
headers = {
          from = '' .. alias_from .. ' ' .. from .. '',
          to = '' .. alias_to .. ' ' .. to .. '',
          subject = subject
},

--Load attachment inside body    
body = {
preamble = "",
[1] = { 
      headers = {
         ["content-type"] = 'application/x-7z-compressed',
         ["content-disposition"] = 'attachment; filename="'..src..'"',
         ["content-description"] = '.. src ..',
         ["content-transfer-encoding"] = "BASE64",
      },
              
      body = ltn12.source.chain(
      ltn12.source.file(io.open(dst, "rb")),
      ltn12.filter.chain(
      mime.encode("base64"),
      mime.wrap()
        )
      )
    },
      epilogue = epilogue
  }
}

--Send the email
r, e = smtp.send(settings)

--Create alert when sending gives an error with error message
if (e) then
  log (e)
  log (r)
  alert("Could not send email: ", e, "\n")
end
log("Send Mail")

--Delete created backup file from tmp folder inside HL
os.execute('cd /lib/genohm-scada/storage && rm -rf user userlib.luas blockly.luas initscript.lua helpers.js genohm-scada.config filter*')