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Issue 315 duplicate DKIM Signatures in one Email Header

S

Snooby

New Pleskian
Hello,

I have an CentOS 7.3 V-Server with Plesk Onyx 17.0.17.

At the moment I have the problem, that some mails from different domains, hosted on my sever, get big headers if they were sent.

I spent much on it, because emails remained in the queue. When I looked at the header of one email, the same DKIM signature was listed 315 times.

Because of that issue, the header becomes to big and some other email providers blocked that mails, because they allow only a header size of 64kb.

On my search, i found a possible solution, because OpenDKIM has in it's config File one parameter say's "RemoveOldSignatures" and it's on default "false".

I don't know if that causes my problem, but i hope that someone can help me.
 
We're seeing this too. When a single email is created by running software (eg. Magento or WHMCS) and sent using SMTP to multiple users (say 2), the header will show 2 DKIM headers.

Depending on the number of users the email is being cc'd to, that number of DKIM signatures appear in the header.
 
But that seems like a bug, if it's like you explained. Because in the header, the DKIM signature is only duplicated without any other information. Even if the email was sent to several addresses via cc, I think one DKIM signature would be enough?
 
Seems like a bug. If we add a third cc: to the email there are 3 DKIM signatures in the header when the server creates an email using SMTP.

I would hope Plesk Onyx programmers are aware of this and a fix is imminent. :)
 
OK thank you for your feedback. I wrote an bug report to the PLESK developers. I hope they can fix it. :)
 
Hello, here are the details:

PRODUCT: Plesk Onyx - Web Pro
VERSION: Version 17.0.17 Update #12, zuletzt aktualisiert: 22. Dez. 2016 00:49:51
OPERATING SYSTEM: CentOS Linux 7.3.1611 (Core)‬
ARCHITECTURE: x86_64

PROBLEM DESCRIPTION:
Some mails from different domains, hosted on my sever, get big headers if they were sent. I spent much on it, because emails remained in the queue. When I looked at the header of one email, the same DKIM signature was listed 315 times. Because of that issue, the header becomes to big and some other email providers blocked that mails, because they allow only a header size of 64kb.

STEPS TO REPRODUCE:
You send an email using an email client like Thunderbird or MS-Outlook and insert for example 3 email-adresses in the "To:" field. When you recive that email on one of the email-adresses and you look in the header, you will see the duplicate DKIM-Signatures. The number of duplicate DKIM-Signatures in the header depends on the number of emails in the "To:" field.

ACTUAL RESULT:
Duplicates DKIM-Signatures depending on the number of email adresses in the "To:" field.

EXPECTED RESULT:
One DKIM-Signature in the header of an email, independent on the number of email adresses in the "To:" field.

ANY ADDITIONAL INFORMATION:
Like in this thread, other useres have this issue with the "CC:" Please read the comment from the user themew: "Seems like a bug. If we add a third cc: to the email there are 3 DKIM signatures in the header when the server creates an email using SMTP."
 
Last edited:
Igor -- is there a page with a list of PPPM's with status? Hoping PPPM-5476 from this thread had been fixed by now :)
 
Still not fixed and happens with php mail, smtp mail, any mail that is cc'd. We've got support tickets that use smtp mail with a dozen duplicate DKIM headers in them... so we wait. :)
 
As far as I know, fix is scheduled to the next major Plesk update.
 
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