Log of events shows mail sent but actually no emails are sent

I am new to phplist
I installed phplist on hosted linode server with ubuntu 20.4, virtualmin, and phplist 3.5.5
After sending mails log of events shows mail sent but actually nothing is sent
I checked ping response from my domain which I am getting successfully

Hey @yashwantj, it could be that the emails are being accepted by your mail server (eg Postfix) but are not stuck in the mail queue there. You should check your mailserver / SMTP settings to see that they work, and that the mailserver your using is working properly.

Hey Samtuke,
Thanks for your quick reply.

Hostname : host.mydomain.com
Username : username@mydomain.com
Password : mypassword
Port : 587

This is my config.php smtp settings

The log doesn’t appear to show any problems connecting to that mailserver, so you should check the mailserver queue to see if the mail is actually being sent. It is possible that the mail is waiting in the queue due to a configuration problem of the mailserver itself (independent of phpList). phpList has no insight into the state of the mailserver queue or its ability to send successfully.

Hey Samtuke,
I found solution for my problem
Problem was from my server side
Outgoing SMTP port was not opened
Now it is opened and my all mails are going out
Thanks for your valuable support