Re: [vps-mail] Large Mailing List

[Patrick Harris <patrick@xxxxxxxxxxxxxxxxxxxx>]

Hello Ed.

I've been running a list via Dadamail (mojo mail) of over 25,000 subscribers for over a year now on a VPS1B.  The client broadcasts 2 to 3 times a week.  Total transmit time is about 3.5 hours each time a message goes out.

Things to watch out for:

• Bounces & error messages.  The amount of data generated by bounces, full mailboxes, etc. is staggering.  200 to 400 mb of log files and bounced messages per week.  You really have to keep on top of these.  I've found that no matter how good the list is, you will always have a problem with approx. 5% of the addresses on the list.  Most issues are temporary problems (could not locate server, mailbox full, out of the office auto-replies, etc.)  5% of 20,000 is 1000 messages x 3 time a week = at least 3000 messages a week that either have to be erased or reviewed.  I spend 1 to 2 hours a week just dealing with the volume of data generated as a by-product of transmitting to the list of 25,000 subscribers.

• Sendmail processes.  It's important to regulate the number of sendmail processes on the server.  We recently ran into an issue where during transmission sendmail was consuming all available processes on the server and prevented Perl from being able to execute.  This generated internal server errors and other related problems.

• Graphics.  If you are going to broadcast html emails you'll have to give a great deal of thought to where the images are going to be hosted.  And you need to optimize the graphics as efficiently as possible.  Even a 1k saving per email adds up fast when sending out to 20,000 subscribers.  For this project, my client maintains one VPS1B for the list (and only the list) and another for hosting graphics for the list's messages.  Even with that sort of seperation, the amount of traffic generated by the image calls from messages to 25,000 subscribers is like 25,000 visitors coming to your site all at once.  The servers hosting the graphics are brought to a crawl if the images are not properly sized.

• Batch processing.  Mojomail allows you to setup transmission via batches.  It's really important to spread out the transmission of messages as much as possible.  That will help with the graphics issues and the overall performance of the machine doing the transmitting.

You should be fine on a VPS2 since you'll have more available processes and a great ability to allocate those processes to specific functions.  The extra diskspace will help as well.

Good luck.

Best regards,

Patrick Harris
Cyberian Frontier, Inc.


On Apr 20, 2004, at 9:26 PM, Ed Greenberg wrote:

> I have a VPS V2 Pro which runs Mailman, among other things.
>
> I have a customer who wants to mail to 19,000 people, three times a week.
>
> Does anyone have experience with a mailing list of that size?
>
> Would Sendmail be able to handle it on that platform?
>
> Thanks,
> </edg> ======================================================================
> This is <vps-mail@xxxxxxxxxxxx>       <http://www.perlcode.org/lists/>
> Before posting a question, please search the archives (see above URL).