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Black hole v. Reject

Community Veteran
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Registered: 10-04-2007

Black hole v. Reject

Will the new platform allow us to specify email addresses that are to be Rejected rather than blackholed?
I have one email address that gets regularly spammed. It is not a valid email address, but is a one character typo of one that is valid. Very occasionally someone makes that typing mistake and sends a genuine email to that address. Because the current blackhole option just means the emails disappear in to the ether, the sender doesn't know that their email didn't get through. For that reason I cannot blackhole that address.
If we could specify prefixes that were to be given a 5xx error I would make use of that option.
At the moment a spammer sending to a blackholed address thinks the email got through. If he were to be given a 5xx error (especially if it was tarpitted), he may remove that address from his list.
jelv (a.k.a Spoon Whittler)
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12 REPLIES
Community Gaffer
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Re: Black hole v. Reject

AFAIK the IronPorts can't easily accept and then discard an email. Anything that gets sent to an email address that isn't defined on the LDAP servers will be bounced with a 550.

Bob Pullen
Plusnet Products Team
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Community Gaffer
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Re: Black hole v. Reject

You get this bounce when you send a message to an undefined mailbox -
This is the Postfix program at host mxout-08.mxes.net.
I'm sorry to have to inform you that your message could not be
delivered to one or more recipients.  Here is the reason why the
message could not be delivered.
<kjahdskjash@bobpullen.plus.com>: host mx-ironport.core.plus.net[84.92.2.97]
    said: 550 #5.1.0 Address rejected kjahdskjash@bobpullen.plus.com (in reply
    to RCPT TO command)

Bob Pullen
Plusnet Products Team
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pierre_pierre
Grafter
Posts: 19,757
Registered: 30-07-2007

Re: Black hole v. Reject

does this mean we will loose unlimited prefixes that get delivered to default if we use catchall?
I have been giving my contacts unique pre codes so that I know if any leak my e-mail address, I do not have mail boxes for them
Community Gaffer
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Re: Black hole v. Reject

No pierre_pierre, catch-all will still work if you have it switched on.

Bob Pullen
Plusnet Products Team
If I've been helpful then please give thanks ⤵

Community Veteran
Posts: 26,344
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Registered: 10-04-2007

Re: Black hole v. Reject

So if we have the catch all on there is no way of rejecting as opposed to blackholing emails.
jelv (a.k.a Spoon Whittler)
   Why I have left Plusnet (warning: long post!)   
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hadden
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Re: Black hole v. Reject

@jelv
At the risk of appearing off-forum, would it work if the problem mailbox was redirected to a known invalid email address, ie one that will definitely get rejected?
At least the sender may get a clue something had gone wrong (even if it confused them a bit)?
Community Veteran
Posts: 26,344
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Registered: 10-04-2007

Re: Black hole v. Reject

I've tried that idea, it nearly works, but doesn't do what I want.
It results in the email being initially accepted and then bounced; this will however be sent back to the sender address which is probably faked by the spammer.
The point of a reject is that the mail server doesn't accept it in the first place.
jelv (a.k.a Spoon Whittler)
   Why I have left Plusnet (warning: long post!)   
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Community Gaffer
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Re: Black hole v. Reject

Quote from: jelv
So if we have the catch all on there is no way of rejecting as opposed to blackholing emails.

No, there isn't.

Bob Pullen
Plusnet Products Team
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Superuser
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Re: Black hole v. Reject

Does Bob's last response also imply that if CATCHALL is not switched on and one has a number of aliases registered against the mailbox name, hen each and every alias has to be made known to IronPort?  If this is corect, will there be action required from users after switch over?
prichardson
Grafter
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Registered: 05-04-2007

Re: Black hole v. Reject

Any settings you gave defined in the current Manage My Mail interface will be retained and operate on the Ironport platform.
No action will be required by any users.
So if your catchall is disabled and you have any alises, redirects or mailboxes, these will be configured to work.
Only addresses which do not exist (no mailbox, redirect or alias) will bounce. By enabling the catchall, you are effectively saying all addresses exist.
techguy
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Re: Black hole v. Reject

I take it if I pointed my domain at plusnet I would be required to accept mail addressed to postmaster as per the RFCs?
Community Gaffer
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Re: Black hole v. Reject

@techguy, yes we'd prefer that you did (it's also part of our T's & C's that you check email sent to this address). Having said that, there are ways to black hole it if needs be.

Bob Pullen
Plusnet Products Team
If I've been helpful then please give thanks ⤵