Increase Dedicated Server Email Per Hour (exim.conf)

I have a ServInt Signature VPS dedicated server ( CentOS 5 - i386 (32-bit), WHM/CPanel). This server is just for our website so I am trying to max out the number of emails I can send per hour.

My current “email per hour” settings for CPanel is UNLIMITED. When I have a few thousand emails in the queue, based on my calculations it is sending about 26 emails per minute or 1560 emails per hour, this is fine but I would like to send more/faster.

The excellent crew at ServInt mentioned I might be able to increase the servers output by changing some “exim.conf” settings. Does anyone have any info on what settings have to be changed in this file? I am interested in doubling or tripling my email output because while we are sending out marketing to opt-in clients, our outbound email is clogged for sometimes up to 20 hours as we send out 30,000 emails to our clients.

Please advise!


Aw, I can’t find it now but there is a setting in WHM which is used to throttle (control the number per hour) outgoing e-mail.



Still trying to work this out, thanks for taking a look DK.

Anyone know how to open up WHM to push out more email per hour?


I would look at as it has several features that allow for what you are after.


Thank you for the suggestion (it applies in my other thread), however in this case I am sure that WHM is maxed out. I need to find a way to configure the server to send more email after it is in the queue.

SwiftMailer will allow you to throttle emails so you don’t have to send them all at once which should help in reducing the maxed-out WHM.


Thanks Steve, but still looking to configure my server. I am already throttling the outgoing email and would like to focus on the original post :slight_smile:

If anyone has any suggestions otherwise, I will take it

Swiftmailer has a anti-flood plugin that so you can limit the number of emails sent through the SMTP at one time. You don’t have to baby sit this as it can be set to stage a batch of emails at predetermined durations. This helps you not run into trouble with your ISP by keeping it in an allowable range.

Some of these tweaks are worth a look:

Also, you can move the spool to a ramdisk if you don’t mind the added risk

Rather than making these mods on a live server, I’d set up a clone vps, and benchmark before/after any tweaks.

Your hourly rate seems quite low, by all means post up your exim conf content, there’s stuff to do with the number of parallel processes in there that might need added.