Building A Good Mailer Program

ccgorman

I've got about 25,000 people in a database that all want to receive company e-mails. I wrote a mailer program so that I could knock up HTML pages and send them off to the people, but now the list is so long that it is causing problems. The server times out, the browser needs to stay open for ages, ... not very economical or robust at the moment

A sample of the code is below, you get the idea, I need a better system, any ideas?

$query="SELECT * FROM user WHERE email<>'' AND subscribe=1";
$query.=" GROUP BY email LIMIT ".$start.",".$limit;
$result=@db_query($query);
while ($details=@db_fetch_array($result)) {
@mail($details["email"],stripslashes($subject),$send_message,$headers."\nContent-Type: text/html; charset=iso-8859-1");
}

drawmack

Instead of sending the email to everyone send it only to one person and then use the bcc header to send it to everyone else. This way php only fires one message to the mail spooler and the spooler does all the work of sending it to 2500 people.

ccgorman

Thanks drawmack,

Is there any way of know the maximum amount of characters that you can send to bcc? Or what about the maximum size a string can be in PHP?

sneakyimp

from the php documentation:

Note:
It is no problem for a string to become very large. There is no practical bound to the size of strings imposed by PHP, so there is no reason at all to worry about long strings.

as for maximum BCC cardinality, not sure. i DO know that when i paste emails into outlook BCC that my email server breaks down if it's more than about 40.

another possibility is to set up a crontab...i.e., scripts executed at intervals. if you want to see some pretty good mailing list code, check out PHPlist...the source code is pretty extensive and it has a lot of features you may or may not want, but it might just do everything you want it to do. it's not hard to install.

dredd

Perhaps I may suggest sifting through the list one-by-one and sending them all individual e-mails.

I had a problem similiar to this before and I solved it by having the page redirect back to itself. The script would simply send off e-mails to twenty people then stuff a variable with the next name and I'd use javascript (not a header tag which didn't help the time-out problem) to redirect back to the page. The script would find the name of the next person in the list then continue on. It would do this over-and-over until everyone had an e-mail.

Hope that helps.