If your email is being returned, there could be several causes – but there’s always an error message to tell you why.
Email is rejected for all kinds of reasons, and sometimes it’s temporary.

If you send an e-mail, only for it to be returned, you’ll get an error message – usually it has the subject line Delivery Failure.
That message includes an error code and even a plain text explanation of what went wrong.
Why is mail returned?
There are a variety of reasons. Here are some common ones with solutions:
- Address does not exist (you may have mis-spelt the email address)
- Recipient’s mailbox is full (nothing you can do about this!)
- Rejected as spam
In each case, the email error message will give the reason for rejection.
Spam rejections can be for all kinds of reasons, but usually it’s the content of the email itself. Some organisations may reject email even if it looks just a little bit like spam.
Very occasionally, one of our mail servers can pop up on a blacklist. If you get a blacklisting error message, try and send the email again – blacklisting should resolve itself within an hour, sometimes less.
If your mail is rejected
Look at the error message first. It will tell you where the problem lies and you may not need to contact us to solve the problem.
If you still can’t see why your email is being rejected, then open a support ticket, making sure you copy and paste the text of the error message into your ticket.