Message Size Limits

  • Lists with fewer than 500 subscribers can send messages up to 30MB.
  • Lists with 500-1000 subscribers can send messages up to 10MB.
  • Lists with over 1000 subscribers are limited to 6MB.

That includes embedded images, attached files, etc. The reason is in the math: a 3MB message multiplied by 1000 copies sent to subscribers equals 3GB of email! A couple of messages of that size submitted by several customers within a few hours can quickly consume all the available working HDD space on our server.

The solution is simple: reduce the size of your message. Some possibilities:

  • If you have embedded an image in the email, remove that and instead insert a LINK to the image, hosted on an image hosting site like Gifyu.
  • If you are sending an attachment, reduce its size (which is usually caused by uncompressed embedded images).
  • Consider putting the attachment on a website instead and just including a link to it in your newsletter. This has the added advantage of not forcing your recipients to each download an attachment which they may not need or want.