Octeth

We made an interview with one of our Oempro users, Dean Collins from YouPlay.com. Dean was having serious slow-sending issue (2 emails per second) on a powerful fully dedicated server. After checking everything, we noticed that the main bottleneck was the server. Now, he’s sending with 18+ emails per second which means ~64,800 emails per hour.

Now, let’s read what Dean suggests for high-speed sending:

Could you please describe yourself and business?

I am a developer at YouPlay, an Australian Casual Game company that specializes in Puzzle Games (Crosswords, Sudoku, Addoku, Word Games, etc). We have quite a large userbase and need to contact them on a regular basis to keep up with site changes and game updates.

What was the problem you were having?
We had just moved our site over to a new set of servers and we needed to send out our first newsletter from the new system. We installed the most recent version of Oempro and set out to test the send speed on the new server setup. As the new server environment was much faster than the old setup we were expecting an increase in send speed (we were getting around 7-11 emails/second with the existing single server setup), to our surprise we were only getting ~2 emails per second on the new setup with a dedicated database server and much more bandwidth available.

What did you check to find the reason of slow-sending?

First step was to track down where the bottleneck was, with the help of Octeth support we commented the various send functions out and then worked our way backwards to find the bottleneck. Not long into the testing phase we discovered that it was in fact the PHP mail() function that was causing the troubles, with the mail() calls commented out we were able to achieve a send speed of 45-50 emails/second (this included all tasks up to the actual send point, e.g compilation, rendering, storage and queuing).

What did you to solve slow sending issue?

To solve the problem we decided to upgrade to the Postfix send engine and see how well it performed, as our servers run RHEL5 the installation process was quite simple and we had the default Postfix engine installed and tested. Configuring Oempro to send via postfix was as easy as changing the sendmail path from /usr/sbin/sendmail to /usr/sbin/sendmail.postfix and we were off.

The first test mailout was running at around 10-12 emails/second and after some minor adjustments (timeouts, bounce handling, DNS configuration, etc) we were already up to 14-16 emails/second.
With some further tweaking and investigation we should be able to squeeze another 8-12 emails/second out of our current setup.

What’s the average send speed you achieved?

For now we have it stable at 14-16 emails/second and we are constantly tweaking settings to get that “sweet spot”. When we are done we are hoping for an average of 25 emails/second and we think this goal will be reached with no problems.

Any suggestions regarding sending performance?

A well known quote comes to mind, “If at first you don’t succeed, try, try again!”. It is really quite simple to get a high average send rate with Oempro and still retain all the dynamic content and tracking features. My first suggestion would be to make sure that you have “embed images” turned off and that you have checked that your PHP’s mail() function can handle the high volume of emails. If possible I would also suggest installing the Postfix mail engine, it will boost your send speed and get you the best results.

Dean Collins can be contacted via dean[dot]collins[at]exemail[dot]com[dot]au or deanc[at]youplay[dot]com

05th Sep 2007, Posted by Cem Hurturk under Newsletter Sending and Deliverability, Sending Performance and Capacity