throtlling outgoing emails

ajna

I have about 38,000 emails that I need to sent to people who have registered with a system...the purpose of the mailing is to both remind members of their association with said web-site and also to allow another bit of programming to catch hard and soft bounces to clean dead emails from the list.

Since this is all done on the fly by checking variables in multiple tables to determine WHO to send mail to, I can't really use an out-of-the-box mailing program. I don't want to constantly export lists from my database to bring into another program, and I don't have time to try and integrate my system with someone elses.

Here is my problem: If I have a cronned or browser-run program running that manages sending out mail toi appropriate members, how can I control the number of emails going out or the speed of these so my server and SMTP is not bogged down. I don't want my entire server to be overwhelmed by this process, but I do want to send the 38,000 emails out without any time-out issues.

Any ideas would be greately appreciated.

Thanks!

etully

If you send out 26 per minute, you will get through all 38,000 emails in 24 hours.
If you drop that to 13 per minute, it will take 48 hours which is probably sufficient and 13 per minute won't put too much stress on the average smtp server.

Add a new field to your database with the emails called "notified". In your mailer script where you select the emails, add "where notified!='yes' limit 13" to the select statement. After you have sent the emails to those 13 people, do an update statement on the database. Set "notified" to "yes" for those 13 email addresses.

Set your cron job to run the mailer script once a minute.

After 48 hours and all the mail has been sent, turn off the cron job and do an update on the database:
update email_list set notified='no';
This way, you will be ready to run the script again next time.

ajna

Well.. I was hoping to avoid using the db to track mail sending, but that seems like a great idea. I will give it a try.

Thanks!

MarkR

You're going to have to remember for each mailing:
- Who it is going to
- What message is being sent
- Who it's been sent to already.

Then your cron script (or persistent server script) can check this data and send them in batches or at a reasonable rate.

If anything fails while you're sending (say the machine needs to be rebooted, or is restarted unexpectedly), you have a record of where you left off so people don't get missed and they don't get sent again.

Bounce processing is an entirely different topic. Typically you'd need to create a mailbox on your server which bounces will arrive in - this is often done automatically in Unix for the user that you're running the web server as (or the user you sent the messages with the envelope sender, if using sendmail -f option as a trusted user).

Then that mailbox should have some filter set up so that a PHP script runs for each message which arrives and:
- Determines whether it is a bounce or not (this is not that easy)
- If it is, tries to determine who it was destined for
- Takes whatever action necessary (e.g. marks their email as bouncing in your database to prevent further messages being sent and notify your admin staff).

Doing all this will involve root access to your mail relaying server, probably. I assume however, that you have that access.

Mark