Check if mail delivered

nobru

Hello everybody,

I have this newsletter tool (based on PHP, using the mail() function).
I would like to know if there is a way to check if the mails sent are properl delivered (I don't want to check if they are read for the moment, one step at a time 😉

Most people told me I cannot check it, but I dont understand, because when using Outlook, I can ask if the mail was received (and also read).

Why couldn't I do it the same way ?

Sorry, my question might not be that clever (I am not a high-tech guy 😉

Thanks in advance for your help,

Nobru

etully

It's a good question.

I know it seems inconsistent that you could do something in Outlook that you can't do in PHP but it's partly true.

First of all, you have less power in Outlook than you seem to think you have. That thing that you claim it can do? It can do it some of the time but not all of the time. When your local copy of Outlook uses a Microsoft Exchange server to send an email to another user who sends/receives email through a MS Exchange server, then you two can check up on eachother if permissions are set to allow that information. However, I don't use a MS Exchange server, and if I did, I wouldn't be using one that permitted remote people to know if I received and read my email. The vast majority of people on the Internet do not use MS Exchange. You can't keep tabs on them. You can only spy on the people who have permitted it in MS Exchange.

Out on the real Internet that most people use, our mail is relayed from server to server with programs like Sendmail and Postfix. Often, our mail goes from server #1, to #2, to #3, to #4 and then to #5 where I retrieve it. Each server in that chain has two jobs: Receive the mail - Deliver to the next server. There is no mechanism in place for sending information backwards to report a successful delivery nor is there a protocol in place to query server #5 (in this example) to test for success or failure of delivery.

This isn't because we don't know how to build such a device. We do. The Internet Gods chose not to. Why? Privacy. It's none of your damn business if I've read my mail yet. It's not even your damn business if it's been delivered.

It's impossible to define what a successful delivery means on the real Internet. For example, if you send an email to me, it goes from your computer, to your ISP, to my ISP, to my company's mail server, to my department's mail server, and finally to my computer on my desk. Which of those points would best be defined as successful delivery? Just because my company has received the email doesn't mean it made it to my department. Just because it made it to my department doesn't mean it made it to my desktop.

Getting delivery messages leaks information. If you can see that I received it, then you know I'm not really on vacation like I said I was. If you can see that I haven't received it, then you know I'm sleeping when you think I should be working. Email is not designed to be a way for people to spy on me. And let's say that it was - or that it should be. Even if email was supposed to be a tool for spying on me, I could configure my department's mail server (not to mention my own PC) to refuse to send out any information about delivery success or failure.

Some people write HTML emails and put graphics in those emails that are called from remote servers. So theoretically, if those graphics get requested from the remote server, then the email must have been delivered and read. However, all modern email software warns the user before getting graphics from a remote server to protect against information leaks.

So, no, it's not possible... unless, like your MS Exchange example, both parties agree to expose their email delivery information.

nobru

etully, thanks for your detailed explanation...
I hoped it would be possible, but I realize now it is going to be difficult.

So if I cannot make sure the mails are delivered, how can I maximize the chances that my mails are not filtered and treated as spam (using the PHP mail() function) ?
Indeed, it seems that some people do not receive them even if I use my own email address as a sender, whereas they would receive it if I send the same email through Outlook for instance...

Could it be that the anti-spam detects that the mail was sent through a loop or something ?

Thanks in advance, again ! 🙂

PS: just for the story, I have just made this test : I sent an email through (MS) oulook (requesting receipt) to my own (MSN) hotmail address, and I got... NO RECEIPT !

etully

Getting mail to pass spam filters is not something I have any experience with.

You have to realize that your email might have to get past more than one spam filter. For example, my ISP chooses not to accept certain mail depending on the source IP address. If it gets past that, then my ISP's mail server filters some mail into their junk filter depending on a ton of different factors. Then, if it gets past that, I have a spam filter on my local computer with a junk filter that depends on a ton of different factors. So there's no one single recipe for making your mail get through. (If there were, the spammers would simply use that recipe and our spam filters wouldn't work).

Making up an answer for you off the top of my head... I'd suggest learning what the spam filters look for and don't do that. Also, you might send out a test email to 2-3 friends to see how their spam filters react (how they score your email) before you send it out widely.

Could it be that the anti-spam detects that the mail was sent through a loop or something ?

Well, mostly no. If an ISP looks at just one piece of email, it is 100% impossible to determine whether or not this email was sent out by a loop in a PHP script that you wrote. However, if you are a really big company (like Comcast, AOL, or Google's Gmail), then you can observe trillions of incoming emails and look for patterns. If Google sees 5000 emails come through in a short period of time that all look basically the same, then they can make an educated guess that these were automatically sent by a loop in a script. And maybe they hold that against you, I don't know.

There are companies who specialize in delivering newsletters on your behalf. They have already dealt with all these issues and know how to do the job. So like a lot of things, it boils down to: Should I spend X hours to learn to do this job or pay $N to someone who already knows how to do it?

dagon

this thread may help http://www.phpbuilder.com/board/showthread.php?t=10362769

Weedpacket

nobru wrote:
Most people told me I cannot check it, but I dont understand, because when using Outlook, I can ask if the mail was received (and also read).

This is done by using MIME email format and adding an extra header called "Disposition-Notification-To:" that contains the email address that the receipt is to be sent back to. (See RFC 3798.)

Obviously, you'll need something watching for incoming mail to see if that receipt arrives.

Whether you get a receipt or not (i.e., whether the email client pays attention to the Disposition-Notification-To: header or not) is of course entirely at the discretion of the user.