opencart get error if i configure smtp on my site

Mail Protocol :smtp
Mail Parameters :
SMTP Hostname :mail.exampal.com
SMTP Username : ***********
SMTP Password : ***********
SMTP Port : 587
SMTP Timeout : 5

my authentication detail is correct

help please ......

==== Required information ====
- iRedMail version (check /etc/iredmail-release):
- Linux/BSD distribution name and version:
- Store mail accounts in which backend (LDAP/MySQL/PGSQL):
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- [IMPORTANT] Related original log or error message is required if you're experiencing an issue.
====