Support Start > Email > Advanced Email Questions > Timeout When Sending Attachments

Customers occasionally ask why they can send “plain” e-mail messages, but see timeout errors in their mail program or Webmail when sending attachments.

If this happens to you, it’s almost certainly not the presence of an attachment per se that’s causing the problem. Rather, a large attachment is probably just making your message thousands of times bigger than a message without an attachment, so it takes thousands of times longer to upload over your connection. Unless you have a fast connection, this can cause timeout errors. (Remember that the “uploading” direction is usually the slow direction for most Internet connections.)

To test this, try sending a small attachment (e.g., a small text file of less than 10 KB in size, not an image file or PDF file). It will probably work. If you then try it with progressively larger attachments, it will take longer and longer, until it eventually takes so long that you find a size that's not practical to send by email over your current connection.

Our page about email size limits has more details and will probably help you decide whether what you’re sending should work, or if it’s just too big.

If you contact us about problems sending email attachments, please be sure to mention the size of the attachment you’re trying to send, as well as the speed of your Internet connection in the “upstream”, uploading direction.