Close smtp mail connection

I am create a cron job function,
Where i want to send more than 300 mail.
Normal new Email(‘default’); can send more than 300 mail.

But when I’m using,
$email = new Email();
$res = $email->setTransport(‘smtpp’); ← SMTP connection

it only send 85 to 95 mails and then show error.

From a post i got "SMTP server has a limit for number of requests in a time interval & a max limit for sending emails per connection, which varies as per different service providers."

Is there anyway to close smtp connection after each mail sent.

You shouldn’t close the smtp connection after each email, this is horribly inefficient since the handshake required for the connection is quite expensive.

Additionally, your SMTP server probably wasn’t setup to allow for bulk mail (this is the case with a regular Gmail SMTP for example) so you should contact your SMTP provider instead.

Ya discuss with the google suite team(we’ve per day 2000 mail allow) they told code issue.

If code issue how 80 - 90 mail sent after that get this “SMTP server did not accept the password.” error.

this error msg present in
\vendor\cakephp\cakephp\src\Mailer\Transport : _auth()

Help me if any solution present.