Ojs is not sending any email

Hello dear Manager of OJS
I hope you are fine.
Unfortunately since the time that we installed OJS during the last 2 years, it is not sending any email to the reviewers, even after the submission of paper by the author the editor is not receiving any email but ater finalizing of the process of sending email it is showing that “the email has been sent to editor or reviewer or for the authors” but in reality none of the above mentioned users are not getting any email .
Would you please guide us in this regard in which part of the setting we need to change based on Our mail setting to active mail sending part for all the users…
our OJS setting is:
SMTP host: mail.ijcua.com
Port: 25
Use SLL: False
Use Authentication: True
Authentication name: editor@ijcua.com
Authentication password: [not applicable]
Email from: editor@ijcua.com
Email to: batuhanyildiz1992@gmail.com
; Use SMTP for sending mail instead of mail()
smtp = On
; SMTP server settings
smtp_server = mail.ijcua.com
smtp_port = 25
; Enable SMTP authentication
; Supported mechanisms: ssl, tls PLAIN, LOGIN, CRAM-MD5, and DIGEST-MD5
smtp_auth = LOGIN
smtp_username = “editor@ijcua.com
smtp_password = “PASSWORD”
; Allow envelope sender to be specified
; (may not be possible with some server configurations)
allow_envelope_sender = Off
; Default envelope sender to use if none is specified elsewhere
default_envelope_sender = “editor@ijcua.com
; Force the default envelope sender (if present)
; This is useful if setting up a site-wide noreply address
; The reply-to field will be set with the reply-to or from address.
; force_default_envelope_sender = Off
; Amount of time required between attempts to send non-editorial emails
; in seconds. This can be used to help prevent email relaying via OJS.
time_between_emails = 3600
; Maximum number of recipients that can be included in a single email
; (either as To:, Cc:, or Bcc: addresses) for a non-priveleged user
max_recipients = 10
; If enabled, email addresses must be validated before login is possible.
require_validation = Off
; Maximum number of days before an unvalidated account expires and is deleted
validation_timeout = 14

What is your server configuration besides OJS configuration? OJS does not send e-mail. It gives it to mail server only.
Please check with hosting comnpany or server administrator what is mail configuration of server.

Dear Mr. Vedran Vucic
Many thanks for you prompt reply.
please find from the attached file of this message the our mail setting.
would you please check if there is anything wrong with that.
Do you have any center to so we can pay and ask them to solve these kind of problems.
since we are not expertise in this field we are just waiting our time by searching about the problems.