Fast email delivery

I have a website that receives incoming emails via cloudmailin, adds the content to the database, and then sends a confirmation email back to the person who sent the email. Currently I'm using a php 开发者_C百科mail() function to send the reply, but it seems to take about 1.5 min to actually get to the user's inbox. Is there a way to make this more instantaneous? I'm currenly hosting the application on FatCow, and I'm sure it has to do with their mail server, but I don't really know much about how that works and am wondering if I have to change hosts to accomplish faster delivery times or if I can do anything about it without switching.

---

mail() is a black box. You're telling PHP to try sending a mail however the host has configured PHP to do so.

It's very likely that it's just calling sendmail in your case. It's also very likely that the mail queue on that machine isn't the fastest in the world. Shared hosting machines are often overloaded.

The very first thing you should do is ask your host about the mail delay. Perhaps something is wrong, and they can fix it. Or they might just tell you that a minute and a half is not a long time to wait.

There are lots of other options, mostly in the form of companies that provide an SMTP service to you. I can't recommend one, but I can recommend that you pop over to your favorite search engine and look for "smtp service." I've recently starting working with Amazon Simple Email Service. It's supposed to be fast and well-maintained, and it's certainly inexpensive.

All of those options are likely going to require some configuration changes on your end. For example, you'll want to set up custom DNS records (for DKIM and SPF) to ensure that mail from a third party provider isn't automatically flagged as spam.

Using SMTP with PHP is dead easy. There are plenty of mail generating options out there. My personal favorite is SwiftMailer. It even has a transport option for Amazon SES.

The final option, of course, is grabbing your own virtual private server or dedicated server, which will let you configure outgoing mail as you desire, at the cost of needing to know how to maintain that server.

---

Edit: Obligatory link to relevant Coding Horror post.