Using mail() to Send to Many Recipients

digitalflash

I put together a php script that allows us to send out mail to a list of subscribers in a database (a little over 1000). It's pretty simple and, when sending to a small number of addresses, it works fine. When we send to the whole list, however, it only sends out to a small portion of the list.

I am not knowledgeable enough to know how to track down what may be happening on the mail server. Could it be that, in trying to send off 1000+ emails at once, the mail server only lets a few through before it chokes on it?

Are there generally agreed upon methods for, say, inserting a little timer function so that it sends off a few, waits a few seconds and sends off another bunch, etc., until email has gone to the whole list?

godwheel

I think the best way to go is to loop send a limited amount of emails, say 25 emails, and pause for 5 seconds before sending the next batch.

Also, are you using BCC or straight To? That could also have an impact.

drew010

the script could be timing out after 30 seconds which is php's default. use ini_set('max_execution_time', 0); to let a script run for an unlimited length of time.

Rodders

You may also want to check that your web host does not impose limits on the number of emails sent from their servers. I recently had a similar problem and found out that I am only allowed to send 200 mails per hour regardless of whether they are individually sent or as one big email with a Bcc list. Basically, each email address was counted towards the 200.

Do you get any error messages in return. We were getting emails sent back to us with various messages. If you are, post them here and I'll try and remember if it's the same.

I've now written a script that will pull the email out of a database and then send up to 180 at a time. I have CRON on my server so I've set it to run every hour and that way I should get round the problem.

Weedpacket

If you're using mail() to send your emails, you may also want to look at finding an SMTP class designed for bulk mailing.

digitalflash

Thanks, guys. Two followup questions...

Do I use -- ini_set('max_execution_time', 0) -- on the script page, or is that a PHP setting on the server?
Does anyone know of a timing loop script I can adapt? I'm not sure if I know how to go at it from scratch. I imagine it would be something along the lines of: while there are addresses remaining, take the next 25 and send them. Wait 5 seconds and repeat.

Among the many things I'm not sure about is how to grab the appropriate rows from the database table. It must be possible to write a query that will grab rows 1 to 25, or 26 - 50, irrespective of any data in those rows.