Problems with emails containing .P7M attachments (which are digitally signed PDF documents)

Kyle Kerst Replied

10/24/2023 at 4:35 PM

Employee Post

Can I have you submit a ticket on this including an example PDF file? I see you've had posts on this once or twice with some limited discussion in the past, are these the same types of files? Perhaps we can have you reevaluate these on the beta? Thanks Gabriele!

Kyle Kerst

Lead Internal Network/System Administrator

SmarterTools Inc.

smartertools.com

Gabriele Maoret - SERSIS Replied

10/24/2023 at 7:24 PM

Hi Kyle!

I'll open a ticket on this tomorrow

Gabriele Maoret - Head of SysAdmins and CISO at SERSIS

Currently manages 6 SmarterMail installations (1 in the cloud for SERSIS which provides services to a few hundred third-party email domains + 5 on-premise for customers who prefer to have their mail server in-house)

Roger Replied

10/24/2023 at 9:55 PM

I think I know this kind of message. Maybe when a Public Cert is published and the sender encrypts the mail but in the receiving mailflow there is no decryption appliance with the private key to decrypt the mail. Decrypting can not be done by smartermail itself.

Gabriele Maoret - SERSIS Replied

10/25/2023 at 1:31 AM

Ticket opened and file attached

Gabriele Maoret - Head of SysAdmins and CISO at SERSIS

Currently manages 6 SmarterMail installations (1 in the cloud for SERSIS which provides services to a few hundred third-party email domains + 5 on-premise for customers who prefer to have their mail server in-house)

Gabriele Maoret - SERSIS Replied

10/25/2023 at 1:49 AM

I add some new info.

This is an example email that has the problem (this is only the case because it contains a .P7M attachment):

However, if I try to "forward", the email becomes readable, even with the .P7M attachment:

It seems that the problem is just a display BUG, not a limitation of the SmarterMail webmail...

Gabriele Maoret - Head of SysAdmins and CISO at SERSIS

Currently manages 6 SmarterMail installations (1 in the cloud for SERSIS which provides services to a few hundred third-party email domains + 5 on-premise for customers who prefer to have their mail server in-house)

Kyle Kerst Replied

10/25/2023 at 6:45 AM

Employee Post

Thanks Gabriele, I'll check out your ticket today. From what I understand though, these types of files (P7M) are encrypted messages rather than encrypted PDF files. If this was simply an encrypted PDF I would expect the message itself to load and display as expected, but in the case of encrypted messages there isn't a decryption mechanism built into webmail that is capable of reading the encrypted contents. We have made improvements in later builds on supporting them client side though (where those mechanisms exist) and so I'd like to see how this setup works in one of our test environments so we can advise you for the future. Have a good one!

Kyle Kerst

Lead Internal Network/System Administrator

SmarterTools Inc.

smartertools.com

Gabriele Maoret - SERSIS Replied

10/25/2023 at 8:07 AM

You're almost right Kyle, they are encrypted CONTAINER (they can contain more than one file), generally used in Italy for signed PDFs, but they can also contain other types of files.

But I wouldn't call them MESSAGES.

BUT the problem is: in SmarterMail webmail, if I write an email (with some descriptive text in the body of the message) and attach a .P7M file to this email, the text in the body of the email also it becomes unreadable, but I still see the .P7M attachment and can download it...

I don't need SmarterMail to decrypt the contents of the .P7M attachment and let me read it (to do this I will download the attachment and open it with the right software on my PC).

What I need is to read the text in the body of the email message, which is written in plain text using SmarterMail webmail...

Gabriele Maoret - Head of SysAdmins and CISO at SERSIS

Currently manages 6 SmarterMail installations (1 in the cloud for SERSIS which provides services to a few hundred third-party email domains + 5 on-premise for customers who prefer to have their mail server in-house)

Employee Replied

10/26/2023 at 10:20 AM

Employee Post

Hi Gabriele,

Thank you for the file you provided in your support ticket. I was able to replicate this behavior. It looks like webmail is replacing the message body with the "This message is encrypted..." warning whenever it detects a P7M file extension. We'll get this resolved!

Gabriele Maoret - SERSIS Replied

10/26/2023 at 10:23 AM

Thx Andrea!

Gabriele Maoret - Head of SysAdmins and CISO at SERSIS

Currently manages 6 SmarterMail installations (1 in the cloud for SERSIS which provides services to a few hundred third-party email domains + 5 on-premise for customers who prefer to have their mail server in-house)

Employee Replied

11/2/2023 at 12:07 PM

Employee Post

Hi Gabriele,

This has been addressed. SmarterMail now distinguishes between an encrypted email and one that simply contains a p7m attachment. You'll see this change in our next BETA release. As such, I'll mark this thread as Resolved.

Kind regards,

Gabriele Maoret - SERSIS Replied

11/2/2023 at 12:21 PM

Thx!

Gabriele Maoret - Head of SysAdmins and CISO at SERSIS

Currently manages 6 SmarterMail installations (1 in the cloud for SERSIS which provides services to a few hundred third-party email domains + 5 on-premise for customers who prefer to have their mail server in-house)

11 Replies

Reply to Thread