@bharat_prajapati You should use the amazon ses api interface instead of the smpt server as that will give a greater throughput. See https://www.phplist.com/?lid=515
There is an error on that documentation page, you need to change this line in your config.php file
define('PHPMAILERHOST', '');
not
define('PHPMAILER', 0);
Whether you can send 30/s will depend a lot on your server capacity.
What method were you using before the change, the SMTP?
You should upgrade to phplist 3.2.6 if you are on an earlier release, otherwise the send rate is the best that can be achieved. The rate will depend on your server capacity but also on how speedily Amazon SES responds.
My hosting support changed some settings in their POSIX relay server and now I have ~18000msg/h.
And I don’t have any settings in config.php file that relates to AWS SES.