Sending Rates & Limitations

Last updated April 17th, 2018

Sending Rates & Limitations FAQ:

Sending emails seems to take a long time with large lists. Can I reduce this?

This usually occurs if you are using the "Popup" window method of sending emails, which usually takes about 1 second every 1 or 2 emails. For larger lists, you should use the 'cron' option, which can send out about 30,000 emails in an hour, depending on server specifications.

My emails are halting or sending very slow. What is the problem?

There are many things that affect the sending rates of Interspire Email Marketer.

  • Sending via cron instead of via the browser, as this means you do not have to load the email for each contact being sent to.
  • Using a lot of images in your email - make sure that you do not embed them and try to avoid large attachments. The size of the email can drastically slow down the send.
  • Your mail server configuration can help or hinder you as well. You should ask your host if they provide any form of mail server optimization or can point you in the right direction for this.
  • The load on your server. If you are on a shared server (or dedicated with a high visit rate) your server can be allocating its resources elsewhere.
  • The power of your server. This is simple, if your server is more powerful then it will be able to process the send easier.
  • Any throttling that your host has in place. If you are on a shared server, hosts will generally place restrictions on the speed that you can send at.

The type of mail server that is installed can have a big effect on Interspire Email Marketer as well. There are 4 main open source ones - sendmail, qmail, postfix and exim. In our tests, sendmail performed the worst, qmail was next, with postfix and exim at the top for performance (they had very similar numbers). I'd suggest getting your host to switch you to postfix based on the performance and also the quality of their documentation.

Another thing to check for is if you have anti-spam software on the server, make sure it's not checking outgoing mail. If it is, it has to scan each email Interspire Email Marketer sends which of course takes time and slows everything down considerably.

Interspire Email Marketer tells me that my send is complete but says that it has sent to less then the total list. Why is this and what can I do?

If Interspire Email Marketer says that it has sent to less then the amount that it should have but also states that it has completed sending then some emails have been rejected from your mail server for some reason. Interspire Email Marketer will simply receive a 'Yes I accepted the email' or 'No I did not accept' message from the mail server. This means that there is no way to determine the exact reason why the message was rejected.

This could be because your host has a per hour sending limit in place to slow down all sending on the server. If this could be the case you should contact your host to see if they have a limit and what it is and then set this limit in the Interspire Email Marketer settings page so that you do not send faster then this limit and risk your emails being blocked by the server.

If this is not the case and your hosts do not have any limitations in place you should ask them to see if the mail server was down for any time whilst your send was in place. If they say that it was not down then you can request the server logs for that time frame to see if there was any errors recorded that may inform you as to what has happened.

How many emails can I send per hour on a BlueHost account?

By default Bluehost have a 50 emails per hour limit set. However, if you contact them and request that your limit be raised they can do this to a maximum of 500 emails per hour.