Why are my discussion emails bouncing?

MemberHub.com features a powerful, private mailing list for each hub. When a member of a hub uses the Discussion interface to create a message, or sends e-mail directly to the hub's mail address, the system will deliver that e-mail to all the members of the hub. Sometimes the e-mail address of a member may have been entered incorrectly, their mailbox may become full, or their e-mail provider may be having server problems. In these cases and many others, the internet e-mail system will notify the sender of an e-mail that could not be delivered. Many refer to this as a 'bounced' e-mail.

What this means for a mailing list on MemberHub.com is that the hub administrators are notified so they can do something to get the member communicating again. You are probably reading this because you have received one of those notifications.

What To Do

Once you identify the e-mail address the bounce notification is about, and you have an idea of why the notification was sent, you can do something about the problem.

E-mail address appears to be spelled wrong and/or the notification indicates that it is being rejected because the domain (yaho.com) is unreachable (retry timeout) or the user is 'not our customer':

  • In this case, you will need to identify the member of your hub who owns the address, contact them by phone/in-person to verify the address and ask them to correct it. You can locate the member by looking through the Members listing. If e-mail addresses aren't showing in the profiles, you will need to turn them on in the Hub Settings -> Profiles tab. Of course, if the owner of the e-mail address is no longer a member of your hub, please consider removing them on the hub's Members listing. This will ensure that they are no longer sent any e-mail from the hub.

E-mail address appears to be correct, but the notification indicates that the e-mail contains spam or a virus:

  • It is possible that there was an e-mail which went through the list with spam-looking content or even a virus. It is best to wait through a few e-mails to see if a pattern forms. If you are confident that the messages do not contain spam or a virus, please contact support@memberhub.zendesk.com so we can help you identify the problem.

The notification is completely unintelligible and you need help:


Interpreting the Bounce

Interpreting the notifications the internet e-mail system sends can sometimes be difficult. Here are some examples of the kinds of notices that go out with a brief description of what they mean. If your notifications are clear enough or you are able to identify the problem through one of these examples, then there should be enough information to resolve the issue.


Each of these notifications will start with a number of 'headers'. You can pretty much ignore these, but there is one that, if present, could very quickly identify the e-mail address of the member that could not be reached. It is 'X-Failed-Recipients'. Please note this does not always exist, and even when it does, it does not tell you why they could not be reached.

In our example above, you can see there is fine text telling us the message came from the 'mail delivery software' and  the error is permanent. A permanent error is typical, though sometimes these notification tell us they will continue to try delivery. What comes after this is what is beyond meaning for most of us. "retry time not reached for any host after a long failure period" (sometimes this is "retry timeout exceeded"). Whatever it means, we can see that billy@exampl.com is probably an invalid e-mail address; shouldn't it be example.com, with an 'e'?

In this example, I have excluded the headers. Notice the notification is pretty much like the other one, except the reason for the failure is quite different. The key here is 'address rejected'. It doesn't tell us why, but it is likely the 'abc.thobo.com' part is a valid server and 'jesseo' is not a valid user there.

"an MX or SRV record indicated no SMTP service", coupled with a user @ yaho.com - we can rest assured there is a misspelling here!

I'll spare you the surroundings and address the notification message. First, there are two addresses that failed, so you'll want to note them both. Second, the cause is "The message was rejected because it contains prohibited virus or spam content".

No one likes the sound of that. Presently, MemberHub.com does not scan mail for viruses before publishing it. It is possible that the e-mail did in fact contain a virus and this user's e-mail server detected it and rejected the email. It is also possible those servers have their spam detector set on high when every other member successfully received a clean e-mail.

You'll want to be careful when these happen. Wait to see if you keep getting them for these e-mail addresses. It may be they reject just one, in which case there isn't much you can do. If there are many similar rejections and you are convinced there is no spam in the e-mails going through the hub, then the user's e-mail service may have blacklisted discuss.memberhub.com. Please contact us at support@memberhub.zendesk.com if this is the case.

This probably means the user part of the e-mail address is wrong.

Have more questions? Submit a request


Please sign in to leave a comment.