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suspend incoming email feature change

Ed Tremble shared this idea 5 years ago
Completed

cPanel has a feature to suspend a mailbox from receiving incoming email, which is nice.


Unfortunately, it does this post receipt as a bounce message from the receiving cPanel server and creates unnecessary backscatter.

Please change this to be done on the SMTP transaction level so the bounce message is generated by the sending server instead.

Best Answer
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Version 60 has gone to the CURRENT tier and includes this interface. You can take a look at the full release notes here:


https://documentation.cpanel.net/display/ALD/60+Release+Notes


If you have any questions, feel free to follow your typical support path, or email me directly!

Comments (10)

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Thank you so much for your submission! I wanted to give you a heads up that, while this is possible, it would require a significant rework or the mail system in order to accomplish it. As a result, we will need to see significant support for this request before any action gets taken. I encourage you to reach out to other users that feel like this is a problem and ensure this request gets votes from those users. Let me know if you have any questions!

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Thank you for your comment Benny.

I understand where you are coming from, and agree that in most cases this may only be an edge case perhaps, if it is seldom used.

I only quickly looked at this behaviour and it seems to be as described, but I didn't spend a lot of time on it.


If it is confirmed though... it is a serious bug that will be opening up cPanel servers all over the world to backscatter whenever anyone enables this option.

Perhaps this would be better off as a bug report ticket rather than a feature request?

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That's entirely possible, but I think it's better (and gets more public exposure) as a feature request than a bug report. I'll bring up your concerns to the product owner for this team and will let you know if anything changes! Feel free to reach out to me directly if you have any other questions or concerns.

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This bad behavior needs to be changed ASAP. Who cares about disk I/O when my IP adddress is going to end up on a blacklist! This bug will cause cPanel servers to become backscatter targets. Being a source of backscatter spam is almost as bad as being an open relay.

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Hey Kevin! The recommended resolution there requires the suspension of DNS services for the domain. While that is one potential solution, it's unlikely that is the route we'll take here. Instead we'd aim to adjust how the bounce emails are managed. I wanted to mention that, until we have a chance to implement this, if you'd like to add it to the suspend-account function, you can do so using standardized hooks. If you're suspending the full account, you could use a script hook. Let me know if you have any other questions!

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You can accomplish a better rendition of this by customizing Exim and adding a hook:


https://forums.cpanel.net/threads/suspended-email-accounts-accept-bounce-mail.536031/#post-2227421

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This is currently merged into cPanel & WHM version 60. We don't currently have a public version of 60 yet, but as soon as we do I'll let you know!

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We run an reasonably large ESP, with many of our clients operating Cpanel/Exim servers. We've noticed that the recent versions of Cpanel are open to backscatter spam, ever since the following prevention technique has stopped working. It's my opinion that Cpanel is now open to backscatter spam as a result of this, and needs to fixed as soon as possible. Here is what used to work:


endpass

message = unknown user

verify = recipient

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We completely agree. It will be fixed in cPanel & WHM version 60. I'm very sorry that it won't be fixed sooner, but as soon as that hits a public release I'll let everyone know!

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Version 60 is now in the EDGE tier. We're hoping to see it move to CURRENT in October.

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Version 60 has gone to the CURRENT tier and includes this interface. You can take a look at the full release notes here:


https://documentation.cpanel.net/display/ALD/60+Release+Notes


If you have any questions, feel free to follow your typical support path, or email me directly!

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