PHP Mailer taking over 30 seconds to send a welcome email

Question

So I am using the PHPMailer library in PHP to send a welcome email when ever my users registered, and it takes so long to do this.

It takes around 30 - 50 seconds to act

Answer 1

Remote SMTP is not really a good thing to use during page submissions - it's often very slow (sometimes deliberately, for greetdelay checks), as you're seeing. The way around it is to always submit to a local (fast) mail server and let it deal with the waiting around, and also handle things like deferred delivery which you can't handle from PHPMailer. You also need to deal with bounces correctly when going that route as you won't get immediate feedback.

That you can often get away with direct delivery doesn't mean it's a reliable approach.

To see what part of the SMTP conversation is taking a long time, set $mailer->SMTPDebug = 2; and watch the output (though don't do that on your live site!).