Skip to main content

Questions tagged [dkim]

DomainKeys Identified Mail (DKIM) is an email authentication method designed to detect email spoofing by allowing the receiving party to verify with the sending party that the email actually originates from their domain.

Filter by
Sorted by
Tagged with
0 votes
1 answer
127 views

Can I use multiple email providers with my website's DKIM, DMARC and SPF?

I'm a software developer, with limited Mail server setup experience, running a little side SAAS on the side where I send emails to my customers. My domain has SPF, DMARC and DKIM setup and I use ...
LePrinceDeDhump's user avatar
1 vote
2 answers
115 views

DKIM Authorization Question

I've read a good bit about DMARC, DKIM, and SPF but now that I'm getting results come in, there are some things I'm seeing that I don't understand. I keep seeing passing DKIM results from outside ...
mirkaim's user avatar
  • 21
3 votes
1 answer
189 views

How to know whether e-mail was spoofed?

I am having a hard time understanding the different methods of e-mail verification. I know about DKIM, SPF and DMARC. If I would like to know whether an e-mail I received actually came from the e-...
LAWYLAWY's user avatar
1 vote
0 answers
181 views

Is my DMARC report saying legitmate emails are failing or illegitimate emails are passing? [closed]

I am learning how to improve email deliverability. Along the way, I'm learning about DMARC reports, SPF and DKIM. I have a friend with a small business who said I can practice with this email ...
learningtech's user avatar
6 votes
1 answer
2k views

Spoofed email sent to me from my email address with SPF/DKIM/DMARC passing

I received an email earlier today on my work email address. The email came from the same address—mine—but I didn't send it. It was an email claiming that he was a professional hacker who had hacked my ...
PaulMcF87's user avatar
  • 161
1 vote
1 answer
1k views

Still able to spoof emails with strict DMARC, SPF and DKIM enabled

Despite setting up strict DMARC, SPF, and having DKIM enabled, I am still easily able to spoof the "From" address. I can easily do this with PHPMailer on my Mac and even with some free 3rd ...
Ian W's user avatar
  • 111
0 votes
1 answer
274 views

Spoofed forwarded email? Help with analyzing of DMARC report

Why did this email get forwarded successfully? An XML report is below: I simply cannot understand the delivery status, a transcript follows: This email has been automatically forwarded. Despite the ...
Vlastimil Burián's user avatar
0 votes
1 answer
320 views

SPF problems using my ISP's SMTP out-bound server

The spf record for my domain is: v=spf1 a:smtp.(my-isp).com ip4:(my-static-IP) -all I have recently added smtp.(my-isp).com to the spf record. I have sent some test emails to gmail where the outgoing ...
Peggy Schafer's user avatar
1 vote
0 answers
190 views

DKIM on Google Workspace not setup yet DKIM check PASSES?

I have a domain that's using Google Workspace that doesn't have DKIM authentication enabled. Even though DKIM isn't set up, emails sent from that domain arrive in other inboxes and pass the DKIM check....
user12102941's user avatar
2 votes
1 answer
697 views

How many times need e-mail headers be signed with DKIM to mitigate DKIM header injection attacks?

Many people have written about DKIM header injection attacks. [1] The suggestion to mitigate it is to oversign headers and to rotate any DKIM keys that were previously used to sign e-mails where not ...
adrelanos's user avatar
  • 784
0 votes
1 answer
2k views

DKIM from another domain, how does it work?

I've recently started configuringn and using DMARC reports and I have the following question. How can the DKIM domain not be my domain (and pass)? I have the following report <record> <row&...
mb14's user avatar
  • 103
1 vote
1 answer
273 views

How do SPF and DKIM work together prevent spoofing?

I'm trying to understand how SPF and DKIM can be used to prevent email spoofing. One of the things I find confusing is that the SSID/AUID of a DKIM signed message can be different from both the ...
jay.lee's user avatar
  • 113
2 votes
0 answers
2k views

DKIM/SPF What does it mean when policy_evaluated fails but auth_results passes?

I am trying to get the DKIM and SPF settings correct for a client who uses both GSuite and WordPress to send her emails. I added this dmarc: v=DMARC1; p=none; rua=mailto:l***@******ney.com; fo=1; ...
OM4U's user avatar
  • 21
1 vote
1 answer
729 views

What’s the purpose of an invalid wildcard DKIM record?

Microsoft and GOV.UK recommend creating a record like the following on any domain that doesn’t send email. TXT *._domainkey v=DKIM1;p= As I understand it, the purpose is to explicitly fail DKIM,...
twhb's user avatar
  • 111
0 votes
1 answer
151 views

DMARC falsely reports impersonation

I have set up DMARC for some months now and I am using dmarc-visualizer to parse the reports. Overall I am happy so we can advance towards BIMI, but before switching to quarantine or reject on DMARC, ...
Alex's user avatar
  • 1
1 vote
1 answer
404 views

Why is DMARC Passing, when it seems like there is no alignment?

I have set adkim=s and aspf=s, the DMARC check on mxtoolbox.com passes all tests. However, I'm using the default DKIM from microsoft, so from my understanding DMARC should fail since the alignment ...
Esteban's user avatar
  • 133
1 vote
1 answer
267 views

Authorizing 3rd Party Envelope Sender to Impersonate Header Sender

Rewriting for clarity: This is regarding emails send from a 3rd party marketer spoofing one of our email addresses in the message header from field. In these emails the envelope sender would come ...
Neobane's user avatar
  • 11
0 votes
1 answer
603 views

How did the email pass DKIM?

I am trying to figure out how this one phishing email (used our Company's domain as from) was able to bypass the O365 Spamfilter. Looking at the Header it looks like they passed the DKIM even though ...
Lephas's user avatar
  • 3
37 votes
2 answers
21k views

How did this paypal spoof email pass SPF, DKIM and DMARC

This mail that got through has me stumped. It appeared to me as being from PayPal <[email protected]> in my Inbox. I happened to look at the original and it says SPF, DKIM and DMARC ...
ianw's user avatar
  • 401
0 votes
1 answer
385 views

Rejected because of DKIM check fail; alignment check fail

I am testing my mail server setup with this tool https://email-test.had.dnsops.gov/ and I am getting suspicious that the tool may not be working right. From what I understand it reports that my ...
MeSo2's user avatar
  • 105
4 votes
3 answers
579 views

What is the point of having SPF and DKIM set up, but having DMARC with policy=none?

Under this FAQ it says that using policy=none is a way for domain owners to monitor forged emails, without having to set up SPF/DKIM. But what im wondering, because i dont fully understand what SPF/...
Flying Thunder's user avatar
0 votes
0 answers
36 views

Why do I need DMARC on top of SPF and DKIM? [duplicate]

If SPF is verifying against a set of IP records if the incoming email from a domain was sent from an authorized host piggybacking on the DNS and DKIM does touch the signature of the email and ...
Asian Flavor's user avatar
0 votes
1 answer
1k views

Whitelisting Email Service for Anti-Spoofing and DMARC

My company uses an Anti-Spoofing Protection based on the SPF Record and has implemented DMARC. Often our users correspond via a "secure" messaging platform like Proofpoint/ZIX/IronPort from ...
user2942358's user avatar
0 votes
0 answers
1k views

Spoofed email? "X-Source-Sender" and "Received" headers look dodgy

I got sent an email from someone in response to an over 2 year old exchange, and the contents of it look like spam to me. Checking the headers the following looks normal: Return-Path Received & ...
Brett's user avatar
  • 279
1 vote
0 answers
485 views

SPF fail, DKIM pass, where did the emails originate from [closed]

I have been a victim of a fraud where my solicitor's email address was used to dupe me out of a house purchase deposit. How do I determine where the emails originated from - did the crooks use emails ...
Claire's user avatar
  • 11
4 votes
1 answer
2k views

Does gmail still ignore DKIM if SPF passes, DMARC style?

This blog post from 2016 shockingly implies that gmail will accept an email if either SPF or DKIM passes. We use G suite SMTP servers, therefore SPF provides almost zero protection from spoofing. Is ...
Morrison's user avatar
1 vote
1 answer
1k views

DKIM and CNAME or DNAME

As far as I understand, there should be no problems with using CNAME or DNAME records in connection with DKIM. That is, while the DKIM record for verifiying a mail from [email protected] wants to be ...
Hagen von Eitzen's user avatar
0 votes
0 answers
313 views

How do I run through the DKIM authentication?

I am currently reading on DKIM authentication for email and I would like to manually try to run through it (to facilitate my understanding of DKIM), but I would like to verify if it is possible to do ...
pikachu's user avatar
  • 11
0 votes
0 answers
45 views

Do we need SPF when we have DKIM? [duplicate]

I always thought that to authenticate email we needed both SPF and DKIM (and DMARC). But email is confusing and recently I found myself asking why we can't do with just SPF or DKIM. I then discovered ...
SWdV's user avatar
  • 199
2 votes
2 answers
4k views

DMARC report for mails I didn't send

I set up DKIM, DMARC and SPF on my domain/server a few years ago, and never touched it again since then. Here are my DNS records (my domain is mydomain.com and my IP addresses are 1.1.1.1 and 2001::1)...
Foo's user avatar
  • 23
0 votes
1 answer
191 views

Theoretical DKIM Question

I have been playing around with sending emails via telnet using text commands. Theoretically... Say I send an email from a typical mail agent that adds a dkim signature from [email protected] to [email protected]. ...
Dedicated Managers's user avatar
2 votes
1 answer
4k views

Why do we need DKIM to be used along with S/Mime?

S/Mime can be used to encrypt email and it can also be used by the sender to provide his digital signature so that the recipient is able to confirm the authenticity of the sender. Why then do we ...
Akash sharma's user avatar
8 votes
3 answers
17k views

Why is DMARC failing when SPF and DKIM are passing?

I've seen this question asked before, but unfortunately, don't understand the responses. I think its something to do with "from" headers being defined differently by different standards. I've added ...
Dedicated Managers's user avatar
3 votes
2 answers
869 views

Does DKIM protect the whole body message?

From RFC6376 #page-29, it says: In hash step 1, the Signer/Verifier MUST hash the message body, canonicalized using the body canonicalization algorithm specified in the "c=" tag and then ...
Rick's user avatar
  • 1,027
7 votes
2 answers
2k views

How did a phishing email pass SPF, DKIM and DMARC?

A friend received a spoofed email (from Bank of America using an uber.com address) which was correctly identified as 'spam' by Gmail. However, looking at the raw message it seems to have passed SPF, ...
Islay's user avatar
  • 591
3 votes
2 answers
266 views

What is the reason for DMARC spec to not require specifically SPF or DKIM pass?

DMARC produces "pass" result if and only if at least one of SPF and DKIM checks pass. It has been noted that DKIM provides stronger protection of the two (if implemented properly). But, in ...
Konstantin Shemyak's user avatar
4 votes
2 answers
278 views

Email verification by sending mail instead of receiving

I have an app whose main purpose is to help people track emails they send. In most user onboarding, The user is sent a secret URL via email. They validate by clicking a link to return the secret. ...
Michael Cole's user avatar
1 vote
2 answers
330 views

SPF, DKIM and DMARC - How do receiving/recipient mail servers know how and when to validate the mail?

I have spent a bit of time researching SPF, DKIM and DMARC mechanisms however If I understand correctly, these help the recipient to confirm whether the domain is legitimate but only if they have ...
Chaplin's user avatar
  • 13
1 vote
1 answer
649 views

dkim passes under a different domain's dkim

I read that a SPF fail with DKIM pass means someone has forwarded an email with our domain name attached. I haven't sent any emails to this domain. Is this domain trying to send emails with my domain? ...
euclid4's user avatar
  • 13
1 vote
1 answer
222 views

What's the use of DKIM/SPF if it only validates the Enveloppe From?

DKIM and SPF are mentioned as powerful mitigations for having your domain abused for phishing. But when I send a mail like this: Return-Path: <[email protected]> From: Citibank security ...
jornane's user avatar
  • 425
1 vote
1 answer
259 views

Understanding DKIM validation

DKIM, as read by rfc4871, states to make address forgery more difficult besides protecting sender identity and integrity of the mail. I have been searching for the details, which precise validation ...
Toni's user avatar
  • 11
0 votes
1 answer
394 views

Giving a PFX cert to a 3rd party email service for DKIM?

My organization is working with a vendor that needs to send emails on our behalf. They want us to import a PFX certificate into a DKIM key. We want to understand the implications first. What ...
Foo Bar's user avatar
  • 367
1 vote
1 answer
473 views

Is it bad to use DKIM DNS without signing mails?

Does it provide any trust at all to have DKIM set up correctly in my DNS but not sign any emails? I could not find any information about that. Now, if I send an email to a domain/server with DMARC ...
Hannes's user avatar
  • 13
7 votes
3 answers
2k views

Why does DKIM verification succeed with a signature from Yahoo when all headers are spoofed to look like GMail?

Today I got a scam e-mail which I decided to disect. I quickly found that it was sent from a GMail address (From, Reply-To, Return-Path) but that the mail itself came from Yahoo. HELO from Yahoo ...
jornane's user avatar
  • 425
2 votes
1 answer
398 views

Is it safe to post the output of Linux dig (DNS) commands?

I need help debugging/troubleshooting a DNS/DKIM issue over on ServerFault, but it looks like I need to paste the results of running: dig my-dns-record.example.com CNAME ...where my-dns-record....
smeeb's user avatar
  • 709
0 votes
1 answer
1k views

How should I configure DMARC (or DKIM?) to deal with OWA forwarding changing email bodies?

For my own domain (mydomain.com, hosted with a free G Suite), I have setup DMARC in testing mode: v=DMARC1; p=none; sp=reject; aspf=s; adkim=s; rua=mailto:[email protected] I have sent out test ...
bers's user avatar
  • 240
1 vote
1 answer
495 views

How to disable email for a subdomain without using SPF

I am working on a tool that checks SPF records, and would like a way to be able to disable email from a testing subdomain, and its children, so that my test domains are not easy targets for spammers ...
jrtapsell's user avatar
  • 3,197
0 votes
1 answer
101 views

Are emails from the Necurs bot net DKIM and/or SPF signed?

As the questions title already asks: Are emails sent by Necurs DKIM and/or SPF signed? Or are they unsigned and simply spoofed?
user165355's user avatar
1 vote
2 answers
701 views

SPF and DKIM passes for SPAM message when using SES and Google Mail

We have websites hosted on AWS, are using SES to send out mailings, and use Google Mail for sending and receiving company mail. Every so often I receive SPAM emails to my Priority Inbox in Google ...
Jordan Reiter's user avatar
10 votes
3 answers
7k views

Finding DKIM selectors without mailing

Is there any way to find out what selectors are used by a domain in their DKIM record without access to an e-mail send from that domain? So to clarify, let's say I know example.com has DKIM ...
Wealot's user avatar
  • 909