CentOS 6, Postfix, OpenDKIM
Have correct DNS records
Sending email using PHP mail() to appmaildev.com - returns auth-report:
SPF result: Pass
DKIM result: fail (wrong body hash: MpaYoPlKy8H4qX8syH3dOM1gPr6spBK5/INxl2X2uNs=)
Tried different solutions - no result
Any ideas?
There are several causes for these two errors: the message may have been modified (perhaps by a mailing list or forwarder) in transit; the signature or hash values may have been calculated or applied incorrectly by the signer; the wrong public key value may have been published in DNS; or the message may have been spoofed by an entity not in possession of the private key needed to calculate a correct signature.
Any way you can check your DKIM entry for your MAIL-FROM domain here
I know this is an older post but, I ran into this issue yesterday. If you are using MailScanner for anti-spam efforts, try disabling the watermarking feature. I found the added watermark headers were invalidating DKIM hashes. Disabling the watermarks allowed the DKIM hashes to be valid. Yahoo was bouncing mail due to this.
As the above poster mentioned, I also had this problem. We use a windows server as our mailserver and we have antivirus installed on it.
It was setup to scan each outgoing message, but this changed the hash / body of each mail, thus failing the DKIM check.
So if you have this wrong body hash error, make sure you don't scan outgoing mails :)
Related
I am building a mailout capability and it is working OK as far as it goes. However, I want to distinguish between various potential (high level) outcomes in order to determine what happens to each message after the current send attempt.
This must be a common requirement so I seem to be missing something pretty obvious, but I can't find anything that addresses it, either here or via Google or on PHPMailer site or .. . Possibly because there are so many questions about specific errors that I just can't find anything useful in all the other results.
At very high level:
Attempt send, and assess resulting error/result. Identify whether this message has been sent, must be retried later, or failed permanently.
- success -> update message status as 'SENT: OK'
- sent, but some issues (e.g. one recipient failed, others processed OK)-> 'SENT: some error'
- failed, due to temporary problem (e.g. connection problem, attachment open) -> 'TRY LATER'
- failed, due to message-specific problem that we should NOT try to resend-> 'FAILED: some error'
As I was unable to find an existing resource with e.g. a table of errors, I spent some time working through the phpmailerException code to try to build one myself, but it's not simple because a) they don't appear to have been designed in terms of this kind of grouping logic, b) it is not easy to uniquely identify a particular error: PHPMailer provides human-friendly messages, which are different in different languages, rather than an identifiable code - given that my solution will need to work across different language installations that's a problem!
Obviously SMTP itself provides a range of errorcodes which I could potentially use for this purpose, but how do I access these via PHPMailer? (This would work for me as I only use SMTP at this point - however, this would NOT work if other message transport like sendmail was used, so I would prefer a PHPMailer solution)
If you want individual result codes for individual address, you really need to send each message separately. If you do get errors on some recipients, they will be listed in the ErrorInfo property - look in the smtpSend function to see how the error string is assembled. I agree that it's not especially easy to parse that info out. The error messages in PHPMailer are generally more for the developer than the end user, so the translations are not that significant. You can get slightly more information about errors if you enable exceptions rather than relying only on return values.
Somebody in my company is being subject to phishing. My first suggestion was just to change the password. However after awhile I received a fake mail from her address again.
Looking at the raw source of the email I found that there is another person's email in X-Sender-ID and I'm wondering who that might be. Is that the person who sent the email or can it be an account that has been hijacked? (I replaced the email with "somebody#host.com")
X-Virus-Scanned: OK
Received: by smtp5.relay.iad3a.emailsrvr.com (Authenticated sender: somebody-AT-host.com) with ESMTPA id DF2788019C;
Fri, 21 Nov 2014 07:54:42 -0500 (EST)
X-Sender-Id: somebody#host.com
Received: from smtp.emailsrvr.com ([UNAVAILABLE]. [2.133.148.211])
by 0.0.0.0:587 (trex/5.3.2);
Fri, 21 Nov 2014 12:54:46 GMT
What is X-Sender-ID? And what is the email it contains?
My deliberations are based on this RFC which describes the Privacy Enhancement for Emails which you are obviously using.
Basically it says about the X-Sender-ID:
[...] encapsulated header field, required for all
privacy-enhanced messages, identifies a message's sender and provides
the sender's IK identification component.
What does this mean?
First of all you have to check if the mail is properly signed. If thats the case you can be sure that somebody#host.com has a certificate. And you can be sure that the mail you received has been sent from this mail address.
I can't tell you the consequences which result out of this fact as I don't know how your company is deploying the certificates etc. ... the mail address/certificate could also have been hacked and thereby abused.
I hope this helps you for your further research.
While #LMF's answer is useful technical information, I'd like to offer a possible alternative explanation.
Spammers who are not familiar with e-mail (and PHP programmers with no other malicious intent) tend to succumb to cargo cult programming when it comes to email headers. In other words, if there is something they don't understand, they might think it does something useful, and include it in their message template.
Without knowledge about your email infrastructure, or other messages of yours to compare to, I would simply assume everything below the top-most Received: header is forged, and basically without meaning.
If you have a system which runs something called trex (maybe this one?) and it really manages to write a Received: header like that, I might be wrong. The format needlessly deviates from the de-facto standard Sendmail template in a few places, but it's not technically wrong (the format is basically free-form, but introducing ad-hoc syntax makes it harder to guess what the fields mean).
Again, more information about what your typical email (and your correspondent's typical mail) looks like, this is heavy on speculation.
The x-sender-id, along with the x-recipient-id are used to specify which interchange key was used in the broadcast of the message.
X-Sender-ID entity_id : issuing_authority : version
X-Recipient-ID entity_id : issuing_authority : version
The first field contains the identity of the sender or receiver. The first field is mandatory, must be unique, and must be formatted as user#host whereas the host is a fully qualified host address.
The second identifies the name of the authority which issued the interchange key.
The third field specifies the specific type of interchange key which was used. This is represented by an alphanumeric string defined by the issuing authority to label and organize the numerous interchange keys issued by that authority. It is recommmended that they use a timestamp but is not always the case.
If the field values of the x-sender-id second and third field are identical to that of the x-recipient-id they may be only listed in the field which is defined last.
Further Reading
"Distributed Computing & Cryptography: Proceedings of a DIMACS Workshop"
I host a spread of different domains that all use my (one) mail-server to send and receive mail. When sending mails, sometimes, my mail gets rejected by the receiving end, marked to the recipient as "suspicious" or simply heads straight for the spam folder.
Also, on the inbound, I get a load of "return receipts" from random victims of spam, where one of my domain names has been used even though the mail never touched my mail server.
I have been told, that both issues stems from the fact, that my SPF record is not set properly which i have been attempting to fix for quite a while now. Unfortunately my basic knowledge of the mechanisms behind the record and the syntax itself escapes me somewhat, which is why I'm looking here for help.
For the purpose of the following example, assume the following setup:
I have two domains: mydomain.com and myotherdomain.com.
Both domains have active subdomains that send and receive mail through my mailserver.
My mail server is named mail.mydomain.com
All running on the same physical server with the IP address: 85.81.xxx.xxx.
I have a semi-static IP-address with my ISP, e.g. it never changes but is per say not mine to call my own. A whois on 85.81.xxx.xxx produces 0x39Axxxx.dslpool.isp.com
Using the tool found at http://tools.bevhost.com/spf/ i end up with the following conclusion:
Email Origin : Pass - 85.81.xx.xx
resolves to
0x39Axxxx.dslpool.isp.com which then
again resolves to 85.81.xx.xx.
Sender Details : Pass -
myname#myotherdomain.net points to a
MX-record that points to my mail sever
at mail.mydomain.net.
Host Name HELO / EHLO : Fail -
mail.mydomian.not resolves to
85.81.xxx.xxx which resolves to
0x39Axxxx.dslpool.isp.com
So, the question is: If at all possible, how would I compose the SPF entries for mydomain.com and myotherdomain.com to disregard this conflict and allow my sent mails to appear valid when spf validated by the receiver?
Hoping for a response ...
Here you should have this SPF entry in your DNS v=spf1 +ip4:85.81.xxx.xxx -all for all your domains, and nothing more in your SPF string.
Make sure that you have such a DNS entry for mail.maydomain.com as well as mydomain.com,
because the SPF entry for mydomain.com is not valid for subdomain.mydomain.com.
If you have many subdomains,you may consider to have an SPF entry for *.maydomain.com. That will take care of all the domain tree that are sub or sub.sub or sub.sub.sub etc. domains of the domain mydomain.com.
I am currently extending an e-mail system with an autoresponse feature. In a dark past, I've seen some awesome mail loops, and I'm now trying to avoid such a thing from happening to me.
I've looked at how other tools ('mailbot', 'vacation') are doing this, grepped my own mail archive for suspicious mail headers, but I wonder if there is something else I can add.
My process at this point:
Refuse if sender address is invalid (this should get rid of messages with <> sender)
Refuse if sender address matches one of the following:
'^root#',
'^hostmaster#',
'^postmaster#',
'^nobody#',
'^www#',
'-request#'
Refuse if one of these headers (after whitespace normalization and lowercasing) is present:
'^precedence: junk$',
'^precedence: bulk$',
'^precedence: list$',
'^list-id:',
'^content-type: multipart/report$',
'^x-autogenerated: reply$',
'^auto-submit: yes$',
'^subject: auto-response$'
Refuse if sender address was already seen by the autoresponder in the recent past.
Refuse if the sender address is my own address :)
Accept and send autoresponse, prepending Auto-response: to the subject, setting headers Precedence: bulk and Auto-Submit: yes to hopefully prevent some remote mailer from propagating the autoresponse any further.
Is there anything I'm missing?
In my research so far I've come up with these rules.
Treat inbound message as autogenerated, ignore it and blacklist the sender if...
Return-Path header is <> or missing/invalid
Auto-Submitted header is present with any value other than "no"
X-Auto-Response-Suppress header is present
In-Reply-To header is missing
Note: If I'm reading RFC3834 correctly, your own programs SHOULD set this, but so far it seems some autoresponders omit this (freshdesk.com)
When sending outbound messages, be sure to...
Set the Auto-Submitted: auto-generated header (or auto-replied as appropriate)
Set your SMTP MAIL FROM: command with the null address <>
Note some delivery services including Amazon SES will set their own value here, so this may not be feasible
Check the recipient against the blacklist built up by the inbound side and abort sending to known autoresponders
Consider sending not more than 1 message per unit time (long like 24 hours) to a given recipient
Notes on other answers and points
I think ignoring Precedence: list messages will cause false positives, at least for my app's configuration
I believe the OP's "auto-submit" rule is a typo and the official header is Auto-Submitted
References
RFC3834
This SO question about Precedence header has several good answers
Wikipedia Email Loop Article
desk.com article
Comments welcome and I'll update this answer as this is a good question and I'd like to see an authoritative answer created.
Update 2014-05-22
To find if an inbound message is an "out-of-office" or other automatic reply, we use that procedure:
First, Find if header "In-Reply-To" is present. If not, that is an auto-reply.
Else, check if 1 of these header is present:
X-Auto-Response-Suppress (any value)
Precedence (value contains bulk, or junk or list)
X-Webmin-Autoreply (value 1)
X-Autogenerated (value Reply)
X-AutoReply (value YES)
Include a phrase like "This is an automatically-generated response" in the body somewhere. If your message body is HTML (not plain text) you can use a style to make it not visible.
Check for this phrase before responding. If it exists, odds are good it's an automated response.
My application uses sendmail to send outbound email. I set the 'From:' address using the following format:
Fred Dibnah <fred#dibnah.com>
I'm also setting the Reply-To and Return-Path headers using the exact same format.
This seems to work in the vast majority of cases but I have seen at least one instance in which this fails, namely when the name part of the above string contains a period (full stop):
Fred Dibnah, Inc. <fred#dibnah.com>
This fails deep inside the TMail code (I'm using Ruby) but it seems like a perfectly valid thing to do.
My question is, should I actually be setting the Return-Path and Reply-To headers using only the email address as opposed to the above Name + Email format? E.g.
fred#dibnah.com
Thanks.
In a situation like this, it is best to turn to the RFCs.
Upon reading up on your question, it appears as if You shouldn't be setting the Return-Path value ever. The final destination SMTP server is supposed to be setting this value as it transitions the message to your mailbox (http://www.faqs.org/rfcs/rfc2821.html starting at 4.4).
According to http://www.faqs.org/rfcs/rfc2822.html the Reply-To field can have the following formats
local-part "#" domain (fred#dibnah.com for example)
display-name (Fred Dibna for example)
I would recommend using option 1 as it seems to be the most basic, and you will likely have less issues with that format. In choosing option 1, your Reply-To field should look like the following:
Reply-To: fred#dibna.com