# Notify about a successfully complete for sign check **URL:** \ **Category:** Gateway\ **Created:** [October 27, 2011, 6:29am UTC](https://community.ciphermail.com/t/notify-about-a-successfully-complete-for-sign-check/240 "2011-10-27T06:29:40Z")\ **Posts on this page:** 8\ **Page:** 1
**Author:** ![matthiasdort1](https://avatars.discourse-cdn.com/v4/letter/m/f04885/32.png) [@matthiasdort1](https://community.ciphermail.com/u/matthiasdort1)\ **Post date:** [October 27, 2011, 6:29am UTC](https://community.ciphermail.com/t/notify-about-a-successfully-complete-for-sign-check/240/1 "2011-10-27T06:29:40Z")
> > **···** > > > Helo, > > > > is there any possibility to notify the receiver for a signd mail about a > > successfully complete sign check? At the moment i can not find any adjustment > > to do that. How does the user konw anything about the sign of a received > > message? > > > > best regards > > > > Matthias ---
**Author:** ![martijn](https://dub1.discourse-cdn.com/flex017/user_avatar/community.ciphermail.com/martijn/32/127_2.png) [@martijn](https://community.ciphermail.com/u/martijn)\ **Post date:** [October 27, 2011, 7:03am UTC](https://community.ciphermail.com/t/notify-about-a-successfully-complete-for-sign-check/240/2 "2011-10-27T07:03:30Z")
I'm not sure I understand you question. What do you mean with "..to notify the receiver for a signd mail about a successfully complete sign check?" Kind regards, Martijn Brinkers > **···** > > On 10/27/2011 08:29 AM, matthiasdort wrote: > > > > is there any possibility to notify the receiver for a signd mail about a > > > successfully complete sign check? At the moment i can not find any adjustment > > > to do that. How does the user konw anything about the sign of a received > > > message? > > -- > Djigzo open source email encryption ---
**Author:** ![lst\_hoe021](https://avatars.discourse-cdn.com/v4/letter/l/58956e/32.png) [@lst\_hoe021](https://community.ciphermail.com/u/lst_hoe021)\ **Post date:** [October 27, 2011, 7:19am UTC](https://community.ciphermail.com/t/notify-about-a-successfully-complete-for-sign-check/240/3 "2011-10-27T07:19:15Z")
Zitat von Martijn Brinkers \: > **···** > > > On 10/27/2011 08:29 AM, matthiasdort wrote: > > > > > > is there any possibility to notify the receiver for a signd mail about a > > > > successfully complete sign check? At the moment i can not find any > > > > adjustment > > > > to do that. How does the user konw anything about the sign of a received > > > > message? > > > > I'm not sure I understand you question. What do you mean with "..to > > notify the receiver for a signd mail about a successfully complete sign > > check?" > > > > Kind regards, > > > > Martijn Brinkers > > I guess something like a "[Signed]" tag in the subject to show the end > user (internal recipient) that the message was signed and could be > verified when hitting the Djigzo Gateway. > > Regards > > Andreas ---
**Author:** ![matthiasdort1](https://avatars.discourse-cdn.com/v4/letter/m/f04885/32.png) [@matthiasdort1](https://community.ciphermail.com/u/matthiasdort1)\ **Post date:** [October 27, 2011, 7:25am UTC](https://community.ciphermail.com/t/notify-about-a-successfully-complete-for-sign-check/240/4 "2011-10-27T07:25:22Z")
> **···** > > > Do Okt 27 2011 09:19:15 CEST von "lst\_hoe02" \ > > Betreff: Re: Notify about a successfully complete for > > signcheck > > > > Zitat von Martijn Brinkers \: > > > > > On 10/27/2011 08:29 AM, matthiasdort wrote: > > > > > > > > is there any possibility to notify the receiver for a signd mail about a > > > > > successfully complete sign check? At the moment i can not find any > > > > > adjustment > > > > > to do that. How does the user konw anything about the sign of a received > > > > > message? > > > > > > I'm not sure I understand you question. What do you mean with "..to > > > notify the receiver for a signd mail about a successfully complete sign > > > check?" > > > > > > Kind regards, > > > > > > Martijn Brinkers > > > > I guess something like a "[Signed]" tag in the subject to show the end > > user (internal recipient) that the message was signed and could be > > verified when hitting the Djigzo Gateway. > > > > Regards > > > > Andreas > > > > Thank you Andreas, yes, this is exactly what i mean. ---
**Author:** ![martijn](https://dub1.discourse-cdn.com/flex017/user_avatar/community.ciphermail.com/martijn/32/127_2.png) [@martijn](https://community.ciphermail.com/u/martijn)\ **Post date:** [October 27, 2011, 8:32am UTC](https://community.ciphermail.com/t/notify-about-a-successfully-complete-for-sign-check/240/5 "2011-10-27T08:32:06Z")
This is not (yet?) supported. The main question is where are you using the tag for? The reason I'm asking is that a tag line can lead to a false sense of security. For example suppose an external sender sends a non-signed message that contains the tag [Signed] in the subject? You might argue that all incoming email should be scanned for such a tag and have the tag be removed. Ok, then what about [signed]? Again you might argue that the scanning should work on a regular expression and should skip all spaces. Ok, then I come up with the following example, {Signed}, or just Signed, or Signd. Just as long as your end-users just use the tag as an indication that the message \*might\* be signed, this should not be a problem. The problem starts when end-users \*assume\* the message is signed and trusted because the subject contains some kind of tag. The best way to detect whether a message is signed and is trusted is by using an S/MIME capable email client. If however you are not using an S/MIME capable email client or are stripping the S/MIME signatures this won't help. The gateway will however add certain header fields which indicate whether the email is signed and whether the signature was trusted/valid etc. Appendix A of the "S/MIME setup guide" briefly explains these headers. Since all X-Djigzo-\* headers are removed from any incoming email, those headers cannot be spoofed. The trouble however with these headers is that it's hard for end-users to read and interpret. To conclude, I'm not saying that adding some kind of keyword/tag to the subject should never be done. But, you should be careful on what it means for your end-users when the subject contains a certain keyword/tag. What is currently missing is a mailet (a mailet is a small piece of software that handles an email) that can add something to the current subject of a message. I will add this to the todo list. If such a mailet is available, you can add this functionality to the xml mail flow specification and match when the email contains the keywords. This might actually be done with Postfix as a workaround. One last question, is there a reason you cannot use an S/MIME email client to check the signatures? Kind regards, Martijn Brinkers > **···** > > On 10/27/2011 09:25 AM, matthiasdort wrote: > > > > > I guess something like a "[Signed]" tag in the subject to show the end > > > > user (internal recipient) that the message was signed and could be > > > > verified when hitting the Djigzo Gateway. > > > > > > Thank you Andreas, yes, this is exactly what i mean. > > -- > Djigzo open source email encryption ---
**Author:** ![lst\_hoe021](https://avatars.discourse-cdn.com/v4/letter/l/58956e/32.png) [@lst\_hoe021](https://community.ciphermail.com/u/lst_hoe021)\ **Post date:** [October 27, 2011, 9:19am UTC](https://community.ciphermail.com/t/notify-about-a-successfully-complete-for-sign-check/240/6 "2011-10-27T09:19:32Z")
Zitat von Martijn Brinkers \: > > > > I guess something like a "[Signed]" tag in the subject to show the end > > > > user (internal recipient) that the message was signed and could be > > > > verified when hitting the Djigzo Gateway. > > > > > > Thank you Andreas, yes, this is exactly what i mean. > > This is not (yet?) supported. The main question is where are you using > the tag for? The reason I'm asking is that a tag line can lead to a > false sense of security. For example suppose an external sender sends a > non-signed message that contains the tag [Signed] in the subject? > You might argue that all incoming email should be scanned for such a tag > and have the tag be removed. Ok, then what about [signed]? Again you > might argue that the scanning should work on a regular expression and > should skip all spaces. Ok, then I come up with the following example, > {Signed}, or just Signed, or Signd. > Just as long as your end-users just use the tag as an indication that > the message \*might\* be signed, this should not be a problem. The problem > starts when end-users \*assume\* the message is signed and trusted because > the subject contains some kind of tag. > > The best way to detect whether a message is signed and is trusted is by > using an S/MIME capable email client. If however you are not using an > S/MIME capable email client or are stripping the S/MIME signatures this > won't help. The gateway will however add certain header fields which > indicate whether the email is signed and whether the signature was > trusted/valid etc. Appendix A of the "S/MIME setup guide" briefly > explains these headers. Since all X-Djigzo-\* headers are removed from > any incoming email, those headers cannot be spoofed. The trouble however > with these headers is that it's hard for end-users to read and interpret. > > To conclude, I'm not saying that adding some kind of keyword/tag to the > subject should never be done. But, you should be careful on what it > means for your end-users when the subject contains a certain keyword/tag. > > What is currently missing is a mailet (a mailet is a small piece of > software that handles an email) that can add something to the current > subject of a message. I will add this to the todo list. If such a mailet > is available, you can add this functionality to the xml mail flow > specification and match when the email contains the keywords. This might > actually be done with Postfix as a workaround. Actually most of the end users don't care or don't have a deep understanding of the security implications anyway. It might be useful to train the users that they can, to some extend rely on a Tag in the subject to: - be sure the sender is really the one claimed - the message was not altered in transit - they can send encrypted mail to that sender This can be spoofed as you said by similar looking Tags, but try to trick the users is at least more difficult then. > One last question, is there a reason you cannot use an S/MIME email > client to check the signatures? There are two possibilities: - We have for example an internal message system which is not S/MIME aware and this might apply to other ticket or workflow based systems as well - The S/MIME handling should be limited to the gateway because the internal certstores are not managed and might not have the CAs needed or more than desired Furthermore this would be easier to support within organisations using many different mailclients with many different UIs showing signed messages in many different ways. But as you noticed it has also disadvantegs. The user should not learn to blindly rely on a subject Tag. But in pratice most of them do not see any difference between a subject Tag and a "signed" Icon in there mailclient anyway ☹ If it is not too much work, i'll vote for it... Regards Andreas > **···** > > > On 10/27/2011 09:25 AM, matthiasdort wrote: ---
**Author:** ![martijn](https://dub1.discourse-cdn.com/flex017/user_avatar/community.ciphermail.com/martijn/32/127_2.png) [@martijn](https://community.ciphermail.com/u/martijn)\ **Post date:** [October 27, 2011, 9:37am UTC](https://community.ciphermail.com/t/notify-about-a-successfully-complete-for-sign-check/240/7 "2011-10-27T09:37:01Z")
I have added a JIRA feature request ([https://jira.djigzo.com/browse/GATEWAY-36](https://jira.djigzo.com/browse/GATEWAY-36)). I don't think it will be included with 2.3.1 release since that has already been "feature freez'd". It will be included after the 2.3.1 release. Kind regards, Martijn > **···** > > On 10/27/2011 11:19 AM, lst\_hoe02(a)kwsoft.de wrote: > > > > \> On 10/27/2011 09:25 AM, matthiasdort wrote: > > > > > > > > > \>\>\>\> I guess something like a "[Signed]" tag in the subject to show the end > > > > > > \>\>\>\> user (internal recipient) that the message was signed and could be > > > > > > \>\>\>\> verified when hitting the Djigzo Gateway. > > > > > > > > > > \>\>\> > > > > > \>\>\> > > > > > \>\>\> > > > > > \>\>\> Thank you Andreas, yes, this is exactly what i mean. > > > > > > \> > > > \> This is not (yet?) supported. The main question is where are you using > > > \> the tag for? The reason I'm asking is that a tag line can lead to a > > > \> false sense of security. For example suppose an external sender sends a > > > \> non-signed message that contains the tag [Signed] in the subject? > > > \> You might argue that all incoming email should be scanned for such a tag > > > \> and have the tag be removed. Ok, then what about [signed]? Again you > > > \> might argue that the scanning should work on a regular expression and > > > \> should skip all spaces. Ok, then I come up with the following example, > > > \> {Signed}, or just Signed, or Signd. > > > \> Just as long as your end-users just use the tag as an indication that > > > \> the message \*might\* be signed, this should not be a problem. The problem > > > \> starts when end-users \*assume\* the message is signed and trusted because > > > \> the subject contains some kind of tag. > > > \> > > > \> The best way to detect whether a message is signed and is trusted is by > > > \> using an S/MIME capable email client. If however you are not using an > > > \> S/MIME capable email client or are stripping the S/MIME signatures this > > > \> won't help. The gateway will however add certain header fields which > > > \> indicate whether the email is signed and whether the signature was > > > \> trusted/valid etc. Appendix A of the "S/MIME setup guide" briefly > > > \> explains these headers. Since all X-Djigzo-\* headers are removed from > > > \> any incoming email, those headers cannot be spoofed. The trouble however > > > \> with these headers is that it's hard for end-users to read and interpret. > > > \> > > > \> To conclude, I'm not saying that adding some kind of keyword/tag to the > > > \> subject should never be done. But, you should be careful on what it > > > \> means for your end-users when the subject contains a certain keyword/tag. > > > \> > > > \> What is currently missing is a mailet (a mailet is a small piece of > > > \> software that handles an email) that can add something to the current > > > \> subject of a message. I will add this to the todo list. If such a mailet > > > \> is available, you can add this functionality to the xml mail flow > > > \> specification and match when the email contains the keywords. This might > > > \> actually be done with Postfix as a workaround. > > > > Actually most of the end users don't care or don't have a deep > > understanding of the security implications anyway. It might be useful > > to train the users that they can, to some extend rely on a Tag in the > > subject to: > > - be sure the sender is really the one claimed > > - the message was not altered in transit > > - they can send encrypted mail to that sender > > > > This can be spoofed as you said by similar looking Tags, but try to > > trick the users is at least more difficult then. > > > > > \> One last question, is there a reason you cannot use an S/MIME email > > > \> client to check the signatures? > > > > There are two possibilities: > > - We have for example an internal message system which is not S/MIME > > aware and this might apply to other ticket or workflow based systems > > as well > > - The S/MIME handling should be limited to the gateway because the > > internal certstores are not managed and might not have the CAs needed > > or more than desired > > > > Furthermore this would be easier to support within organisations using > > many different mailclients with many different UIs showing signed > > messages in many different ways. > > > > But as you noticed it has also disadvantegs. The user should not learn > > to blindly rely on a subject Tag. But in pratice most of them do not > > see any difference between a subject Tag and a "signed" Icon in there > > mailclient anyway ☹ > > > > If it is not too much work, i'll vote for it... > > -- > Djigzo open source email encryption ---
**Author:** ![matthiasdort1](https://avatars.discourse-cdn.com/v4/letter/m/f04885/32.png) [@matthiasdort1](https://community.ciphermail.com/u/matthiasdort1)\ **Post date:** [October 27, 2011, 10:13am UTC](https://community.ciphermail.com/t/notify-about-a-successfully-complete-for-sign-check/240/8 "2011-10-27T10:13:42Z")
> Do Okt 27 2011 10:32:06 CEST von "Martijn Brinkers" \ > Betreff: Re: Notify about a successfully complete forsigncheck > > > > > I guess something like a "[Signed]" tag in the subject to show the end > > > > user (internal recipient) that the message was signed and could be > > > > verified when hitting the Djigzo Gateway. > > > > > > Thank you Andreas, yes, this is exactly what i mean. > > This is not (yet?) supported. The main question is where are you using > the tag for? The reason I'm asking is that a tag line can lead to a > false sense of security. For example suppose an external sender sends a > non-signed message that contains the tag [Signed] in the subject? > You might argue that all incoming email should be scanned for such a tag > and have the tag be removed. Ok, then what about [signed]? Again you > might argue that the scanning should work on a regular expression and > should skip all spaces. Ok, then I come up with the following example, > {Signed}, or just Signed, or Signd. > Just as long as your end-users just use the tag as an indication that > the message \*might\* be signed, this should not be a problem. The problem > starts when end-users \*assume\* the message is signed and trusted because > the subject contains some kind of tag. > > The best way to detect whether a message is signed and is trusted is by > using an S/MIME capable email client. If however you are not using an > S/MIME capable email client or are stripping the S/MIME signatures this > won't help. The gateway will however add certain header fields which > indicate whether the email is signed and whether the signature was > trusted/valid etc. Appendix A of the "S/MIME setup guide" briefly > explains these headers. Since all X-Djigzo-\* headers are removed from > any incoming email, those headers cannot be spoofed. The trouble however > with these headers is that it's hard for end-users to read and interpret. > > To conclude, I'm not saying that adding some kind of keyword/tag to the > subject should never be done. But, you should be careful on what it > means for your end-users when the subject contains a certain keyword/tag. > > What is currently missing is a mailet (a mailet is a small piece of > software that handles an email) that can add something to the current > subject of a message. I will add this to the todo list. If such a mailet > is available, you can add this functionality to the xml mail flow > specification and match when the email contains the keywords. This might > actually be done with Postfix as a workaround. > > One last question, is there a reason you cannot use an S/MIME email > client to check the signatures? > > Kind regards, > > Martijn Brinkers > > -- > Djigzo open source email encryption > \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_ > Users mailing list > Users(a)lists.djigzo.com > [http://lists.djigzo.com/lists/listinfo/users](http://lists.djigzo.com/lists/listinfo/users) ok, thank you for your detailed answer! i have understand the problem with a tag in subject and the possibility of fake. An other way to give the (intern) user a notice about a successfull signcheck may be send a special mail with subject related to the original mail, analog the notice about an successfull encryption. Kind regards Matthias > **···** > > > On 10/27/2011 09:25 AM, matthiasdort wrote: