Expected response code 250 but got code "421", with message "421 Timeout waiting for data from client.

[pmoubed]

This happens when I use it with AWS and For Loop to send emails. I don't use spool.

[dmcfaul]

Is this issue going to be looked at? I have the same issue. The connection times out, would be nice if there was a reconnect method that I could use when this is thrown.

[dmcfaul]

looks like if you do a:
$mailer->getTransport()->stop();
Swiftmailer will then reconnect automatically. So just catch the Exception in a try/catch and then stop and retry sending.

[kgreen169]

It's 2018 and I am having this exact same problem. I have tried multiple ways to get around this error. Here is my latest
try {
$sendSuccess .= $mailer->send($message, $failedRecipients);
} catch (Swift_TransportException $ste) {
$mailSuccess .= "
Caught Swift_TransportException ste calling mailer->send
";
$mailSuccess .= $ste->getMessage();
$mailSuccess .= "
End ste->getMessage. Stoping transport
";
$mailer->getTransport()->stop();
$sendSuccess .= $mailer->send($message, $failedRecipients);
}
not sure if I am using ->stop correctly

Still got exception
Expected response code 250 but got code "421", with message "421 4.7.0 Try again later, closing connection. (MAIL) k130-v6sm1483348itb.0 - gsmtp "\