Questions tagged [smime]

S/MIME is a protocol for signing and/or encrypting emails using certificates

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Using openssl smime to email binary files on Linux

I want to be able to send automated encrypted email from Linux to Microsoft Outlook user’s email. I know little about S/MIME but I have managed to accomplish sending encrypted text emails using this ...
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Which clients support self-signed certificates with DANE?

We've been considering to make more use of DANE as a decentralised authority for our certificates. Especially with S/MIME. However, the key obstacle is... how widely are DANE treated as an authority ...
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Do expired, revoked, self-signed S/MIME certificates trigger email SPAM filters or affect mail delivery?

For example, I have an expired or revoked S/MIME certificate. Can I sign or can the recipient encrypt a message with it? Will an email client allow it? If it is possible, will the message be rejected ...
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Is the private key for S/MIME certificates generated on the CA servers or in the browser?

I heard that some certificate authorities generate your private key for S/MIME certificates on their servers. However, some of them who recommend using Internet Explorer for this purpose, probably, ...
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How is outgoing email encrypted by S/MIME certificates?

After several hours of surfing the internet, I failed to find any comprehensive guide on how to encrypt the email between two users using the S/MIME certificate. In parallel with SSL certificates: ...
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Outlook sMIME certificates location, errors, and background work

We have an situation. Our customer can get sMIME encrypted mails and reply to that email. But when he wants to send it with new email he is getting an error message as if the recipient email does not ...
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Cannot recover backup made with `openssl smime`

My (only) database server went down and I am in the process of recovering everything. I created a new server and now I just want to restore the database backup. I have a nightly script that runs this ...
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Digital Signature is not valid

I recently received a digital signed email from a friend and the certificate is issued by COMODO RSA Client Authentication and Secure Email. My problem is the thunderbird detect it as a "Not Valid ...
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What are the best practices for providing S/MIME-Certificates in Outlook?

I got some questions regarding S/MIME in Outlook and certificates in general. Some questions arrised about the possibility to digitally sign emails in my company. As I'm new to the topic I had to do ...
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Scan S/MIME Encrypted Email on Exchange Server

We have a copy of each user's S/MIME encryption (well, decryption) private keys as well as their certificate centrally managed in an HSM. We want to configure Exchange to automatically decrypt any ...
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How can I select a certificate from a PEM file with multiple certificates?

Background info: I am working on an OS X server, and I need to use certificates from the key chain with openssl smime in order to encrypt messages in a bash script. In order to do so, I use the ...
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Email signing using commercial SSL certificate

I am considering securing my work environment with certificates and thus have a couple of questions. My Active Directory domain is domain.com. If I buy a commercial wildcard SSL certificate from i.e. ...
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Verifying S/MIME signed message with OpenSSL without checking the certificate's purpose

The problem: When I sign a message with a certificate which is used for a HTTPS webserver, OpenSSL does not want to verify it back. Signing a message: echo "TestMessage" | openssl smime \ -sign ...
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AD Certificate template - Enroll on behalf of

I'm trying to setup S/MIME for a few users, which requires certificates. I'm not using smartcards, and not using autoenrollment for these certificates. Server is running 2012R2. I created a ...
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openssl smime message signing: why do I need a -certfile key?

Here is how one should sign a message with openssl smime? according to the docs openssl smime -sign -in in.txt -text -out mail.msg -signer mycert.pem \ -inkey mykey.pem -certfile mycerts.pem But ...
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Generating public/private credentials for MS Outlook email encryption

An app running on a CentOS 7 web server needs to receive encrypted emails sent from users of MS Outlook. Can someone please provide explicit instructions as to how I can generate or procure all of ...
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Smart Card S/MIME with Exchange 2013

I have an Exchange 2013 environment that I'm trying to implement S/MIME with smart cards. To the best of my knowledge, and the little help I have received on TechNet, I have configured my Exchange ...
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Automatic S/MIME certificate distribution/outlook integration for signed/encrypted email

I have a Windows Server 2008 R2 Machine and an Exchange 2010 Server on two seperate machines. The WS2008R2 machine is configured with a certificate authority in which I have configured certificate ...
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S/MIME: signed mails with disclaimer from mail filter/mailscanner?

We have a Mailscanner, which scans incoming and outgoing mails and add a small disclaimer (Mail was checked for Viruses... bla bla bla). So far i can add a disclaimer without signing the mail, or ...
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Are External LDAP referrals similar to a DNS Recursive or non recursive entry?

I'm very familiar with DNS, but less so with LDAP. In DNS I have the ability to delegate the CPU and IO load of referral chasing a given DNS query... or I can set norecurse and have the client ...
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1 vote
1 answer
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How can I limit the SMIME capabilities from a CA without using FIM?

These instructions describe how to prevent using SMIME with weak ciphers, however it requires an expensive product from Microsoft. How can I prevent a CA from issuing SMIME certificates that permit ...
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Possible to make SMIME signatures not appear as an attachment? (e.g. in Gmail)

We are using SMIME across our organisation and are getting complaints that the SMIME signature is appearing as an attachment in various email clients. (gmail) Is there any way to edit the SMTP ...
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4 votes
2 answers
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Is it generally acceptable to expose LDAP in read only mode to the Internet?

I need to support Mac clients who need to access a LDAP server to locate SMIME keys. Since the keys are already in AD, and it's easy for me to create a RODC or read only forest where I push the ...
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1 answer
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S/MIME icon missing from OWA

I'm trying to test S/MIME with OWA (Exchange 2010, Outlook 2010). Now my research has told me that the control must be installed first. So as someone with admin rights, open OWA, click on All Option, ...
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How do I configure AD CS to support Name Constraints (4.2.1.11 in RFC 2459)?

I am trying to figure out how to do Qualified Subordination with the critical extension set, but I'm unable to figure out how to do this in MSFT AD CS. For a given certificate, how do I make sure ...
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How to setup an openldap addressbook for thunderbird secure s/mime email ?

I want to setup an ldap server that will hold an addressbook of users their emails their smime certificates. I want to use this ldap server as an addressbook in thunderbird and/or other mail clients ...
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1 answer
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Sign outgoing mails automatically with postfix (S/MIME)

I want to sign outgoing mails automatically with postfix. I've found a script and integrated it into postfix. That works mostly like expected, but it has two bugs and I hope you can help me to fix ...
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2 votes
2 answers
652 views

How can I confirm which specific S/MIME public key was used to encrypt an email?

CentOS 5.8 Is there an easy way to tell what specific public key was used to encrypt an email? My email gateway isn't able to decrypt an inbound S/MIME message and I'm suspecting that the remote ...
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2 votes
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mutt, smime, decrypt with one of two different keys

This is an odd one. We want to have an encrypted e-mail list. There are a few ways to do this, but in the interim what we've done is created a public/private keypair via openssl for our e-mail list (...
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5 votes
3 answers
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Is there a way to make encryption default per contact in Thunderbird?

I administer several computers that have Thunderbird installed. I know Thunderbird has an option to require all email to be encrypted. However, I would like a way to allow unencrypted email normally,...
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Outlook Encrypted Emails boo boo

I just reinstalled my Windows OS 7 and forgot to backup my Email Certificate for Outlook 2010 beforehand. Now I can't read any encrypted emails. When I try, it says "Cannot open this item. Your ...
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Can I configure mailman so that it won't break S/MIME digital signatures?

We're currently using Mailman as a mailing list manager. Mailman modifies the content of mail messages. The problem is that some of our users are sending digitally signed messages and the modification ...
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1 vote
1 answer
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Secure e-mail with SMTP Virtual Server in Windows 2008

Is it possible to send encrypted and digitally signed e-mail messages using S/MIME through the SMTP Virtual Server component included in Windows Server 2008 or do I have to use Exchange? If it is, ...
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1 vote
2 answers
2k views

Any web email providers that support sending and receiving S/MIME encrypted email? [closed]

Can anyone suggest a webmail provider (like gmail, Yahoo mail, hotmail, etc.) that supports S/MIME encrypted email well? Both sending and receiving email and obviously keeping track of the encryption ...
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