WHY is mail() a bad choice?

[Anon]

Mail() seems to be a weak point of PHP.

Someone made the following comment on Devshed.com:

"mail() is NOT a function to use in mailing large lists, (large means more then 100)!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!"

I've heard before that mail() isn't strong enough for large lists.

What I want to know is WHY (i.e. the reason and what would HAPPEN if mail() was used for a large list), and what a stronger alternative is... a PHP alternative if there is one. Some other language (Perl I guess) if there is no PHP alternative.

I just want to know what professional scripters use in their mailing list scripts.

Thanks.

P.S. What size a list can mail() handle before bad things start to happen? Surely 100 is manageable.

[kparker]

It's just that mail() is a high-overhead way to send out messages. The number 100 isn't hard-and-fast; it's just a swag based on someone's experience. When you hit the specific limit for your environment, you'll find your machine can't keep up with all the mail to send out.

[Anon]

Thanks for your quick response.

What can I use instead of mail()?

If I pause the sendout during the running of my script (i.e. pause every 50 emails for 30 secs) will that make it more feasible?

[brandonschnell]

i've put a throttle on my emailer scripts to send out one or two emails a second and i've tested it sending out 10,000+ emails without any problems or slow down to the system.

[Anon]

Nice! What I wanted to hear 🙂

Are you on a dedicated or shared machine?

Would you mind sharing your code with us? It'd be good to see what exactly lies behind your success.

Also, how do you prevent connection timeouts?

[brandonschnell]

dedicated.

the code is part of a project i did and the email portion was tightly tied into the system. basically the user would choose to send an email out and the system would dump the email addresses, names, and template ids into a queue table. a cron job would pick up a couple emails from the queue job table and send them out.

you could probably just use a large while loop and use the php function usleep() to prevent php from overloading the smtp server. for example, set usleep() to delay execution by a half a second before it runs through the while loop again.

in my testing on a couple of systems i've never had problems with timing out when the script is run from a crontab.

http://www.php.net/manual/pt_BR/html/function.sleep.html

[reeferd]

If you send something for the browser to show for every loop the script makes, the page won`t time out.

You can use flush to do this...

[Anon]

you dont have to send any output and wait... just set

1) SCRIPT TIMEOUT
2) NOUSERABORT -- i dont remember the name

then you can execute loop with 10000 emails and close your browser and go to sleep :-)

mail() is really a dumb one, i have no idea how to send LOTS of emails on shared machine. even hosting company didnt give me a good solution.

[reeferd]

It didn`t work for me to adjust the script timeout in php.ini, but maybe I did it wrong.. 🙂

Never heard of that "nouserabort"

How does that work?

-trond

[Anon]

You can use sockets to open a connection to your SMTP server. That's probably the easiest way to do it. You can re-use the same connection, too.

<open connection to smtp server>
send mail 1
send mail 2
...
send mail 3,554,344,632
send mail 3,554,344,633
<close connection>

[dmcinnis]

Okay, now I am interested. Can you be more specific as how to accomplish this?

David

[kparker]

There's probably something around here on talking to smtp servers.
But basically, you just open a socket to the server, and speak SMTP
to it. Get the RFQ (sorry, I don't remember the number) and find
out all the gory details, but a simple transaction looks like this (the
SMTP server says the lines in italics, you say the other ones.):

<i>220 mail.null.com ESMTP Sendmail ...</i>
HELO fly-by-night
<i>250 mail.null.com Hello fly-by-night [10.0.0.1], pleased to meet you</i>
MAIL FROM: &lt;[e-mail]&gt;
<i>250 &lt;[e-mail]&gt;... Sender ok</i>
RCPT TO: &lt;[e-mail]&gt;
<i>250 &lt;[e-mail]&gt;... Recipient ok</i>
DATA
<i>354 Enter mail, end with "." on a line by itself</i>
From: [e-mail]
To: [e-mail]
Subject: Sample SMTP transaction

This is the body of the email.
..
Be sure to double any period that occurs on a line
by itself in the body of the message, otherwise the
message will end prematurely!
.
<i>250 WAA05710 Message accepted for delivery</i>
quit

Note that the numeric code at the beginning of the server lines tells you everything you need to know about the server status; the rest is just for human readers (including for logging purposes.)

Note, too, that you can include as many RCPT TO: lines as you wish, to send the body of the message to any number of recipients.

And finally, the header lines that the recipient sees turn out not to be headers at all, from the pov of the smtp server: these all go at the head of the body of the message, right after the DATA command.

[reeferd]

This was cool! Thanks a million Kirk Parker!
I am gonna try this out for sure! 🙂