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Questions tagged [dkim]

DomainKeys Identified Mail is a scheme for signing and verifying email messages to confirm that that the source hasn't been forged, and is typically implemented by MTAs. The source MTA adds a header to the message body containing a signature, and the destination MTA verifies this signature against a key retrieved from DNS.

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DKIM signing not working with Exim4

As I'm new into servers but really interested, I have decided to set up VPS on external hosting(in my case Contabo) and host my own email/website there. I have watched a youtube tutorial(This one on ...
Alexander's user avatar
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51 views

What are these DMARC failures about?

I've been toying with dmarc off and on for the last couple of months. Currently I have no policy set. I am using URIReports for report collection and analysis. Most of the results are good. We use ...
Rob Brandt's user avatar
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Postfix body hash did not verify / First Hop of headers contains local address

So far my mailserver works, all checks pass with almost highest scores. But one thing I wonder is why I get a DKIM authenticated problem on mxtoolbox, when sending a mail via smtp. Screenshot 1 ...
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Your DKIM signature is not valid - opendkim

I'm running postfix server with few "features" like spf, dmarc and DKIM. SPF and DMARC works fine and when I sent an email to my gmail account I see they PASS, however DKIM shows "FAIL&...
kubn2's user avatar
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3 votes
1 answer
383 views

How to get SPF alignment to pass DMARC for a subdomain?

I have the following DNS configuration: $ dig +noall +answer -t txt example.com example.com. 626 IN TXT "v=spf1 +a +mx include:sendgrid.net include:_spf.google.com -all" $ dig +noall +...
tftd's user avatar
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121 views

This relay isn't allowed to send mail "From" gmail.com

I'm on GoDaddy and since about January 2024, I've been getting this message from various gmail and yahoo accounts: ECDHE-RSA-AES256-GCM-SHA384:256 CV=yes: SMTP error from remote mail server after end ...
user1409214's user avatar
-1 votes
1 answer
60 views

Phishing email but with SPF, DKIM and DMARC in "PASS" status

I received an email from a company that looked fine. Gmail deemed it ok. I checked the domain and the various DMARC, DKIM and SPF headers: they are all in "PASS" status. The sender's IP also ...
sqrt-1's user avatar
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1 answer
307 views

SPF spf.protection.outlook.com is invalid for messages within tenant

When sending mails through our Exchange 365 service those mails get through successfully, but if we look at the mail headers we see that where the sender and recipient are in our tenant the mail's ...
JohnLBevan's user avatar
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2 votes
0 answers
150 views

How to capture incoming emails on exchange before they reach transport agents?

I'm trying to debug why some inbound emails are failing DKIM checks. I'm running the latest version of Microsoft Exchange server 2019 on Widows Server 2022. I have enabled pipeline tracing via the ...
Danny.Ando's user avatar
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67 views

DKIM settings with Amazon SES not finding primary domain

I'm attempting to send email via Amazon SES with a custom domain. I have one domain that works and the DKIM headers that come to my gmail account look like: Authentication-Results: mx.google.com; ...
stdunbar's user avatar
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Can I have more than one public keys saved in one selector for dkim?

The question is easy to understand, but it might be confusing. I understand that I can host multiple selectors for a DKIM record, but just out of curiosity, can I have multiple keys per selector in a ...
SUNITA GUPTA's user avatar
0 votes
2 answers
256 views

Why does my DMARC report from Google have "<dkim>fail</dkim>" when all auth_results have "pass"

We're using Microsoft 365 (outlook.office.com) for our company emails and have had DKIM set up for a while, but recently added a DMARC record. I now got a DMARC report from Google where every record ...
EM0's user avatar
  • 329
0 votes
1 answer
153 views

DKIM signing - does it matter which transport agent does the signature

I am quite new to the dkim area. I understand how it works but some details, i am missing. Let's say, i have a mail server that contains user boxes (Exchange) and an edge server that just transports ...
atapaka's user avatar
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0 votes
2 answers
270 views

Forwarding email message breaks DKIM

I have problem with postfix, DKIM and forwarding messages. In almost every article about DKIM I’m reading that “if I do not modify any fields in message header, DKIM signature should still be valid ...
user71061's user avatar
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0 votes
1 answer
204 views

Original DKIM signing is not sent when using SMTP relay

We are using a VPS (ubuntu 18, postfix) to send mails for multiple domains hosted on a server (AlmaLinux 8). For example from the domain "domain.com". VPS is maildomain.com Hosting server ...
Denis's user avatar
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2 votes
2 answers
509 views

Add Multiple Subdomains In Signing Table And Key Table Opendkim

I need some major help adding multiple subdomains in the signing table and key table for opendkim without listing them one by one. If I have 50 subdomains I want to add, it will take me forever. I am ...
Digital Joe George's user avatar
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0 answers
159 views

DKIM file not found with Rspamd and a DKIM selector map

I am running into an error with Rspamd where my dkim signing file is not being found. The exact error message is dkim_module_load_key_format: cannot load dkim key /var/lib/rspamd/dkim/mydomain.com....
Niels Koop's user avatar
0 votes
0 answers
133 views

Is possible to use a DKIM-Proxy to signing emails requested from another application?

I using an application to send emails, written in golang which use net/smtp as SMTP Libary, however that lib provide no support with DKIM signing, but using a sendmail command, for example, the DKIM ...
Shinomoto Asakura's user avatar
0 votes
1 answer
73 views

OpenDKIM not signing e-mails from host10.example.com

I have a server, called host10.example.com which sends administrative e-mails by mailx commands to myself only. These outgoing e-mails need to be signed by OpenDKIM. I have tried many configurations ...
Ned64's user avatar
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1 vote
1 answer
146 views

How OpenDKIM decides which emails to sign?

In OpenDKIM, what domain does it consider to use when comparing to internal hosts? Do it consider the domain of Return-Path (i.e. envelope MAIL FROM's domain) or header From or HELO's domain.
Ayush Gupta's user avatar
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0 answers
50 views

What is behaviour of opendkim while verifying an email with multiple dkim signatures?

I am trying to implement DKIM verification using Opendkim and postfix. The doubt I am struck by is what will happen if the email has more than one DKIM signature and one of them fails (as like failed ...
Ayush Gupta's user avatar
1 vote
0 answers
182 views

What are typically the headers which I should oversign?

I am trying to setup MTA using Postfix and using opendkim for dkim signing. When I went through opemdkim documentation it have a field which is named 'OversignHeaders' document describes it as: "...
Ayush Gupta's user avatar
0 votes
1 answer
128 views

What does "--[no]subdomains" option in opendkim-genkey mean?

Based on the documentation --nosubdomains "Disallows subdomain signing by this key". But didn't we need to create separate DKIM records for subdomains regardless? Please correct me if I am ...
Ayush Gupta's user avatar
-1 votes
1 answer
385 views

Create a pair of keys suitable for DKIM setup using ssh-keygen

Question What is the right way to create a pair of keys suitable for DKIM setup using ssh-keygen? Given the corresponding solution with openssl: # creates a private key openssl genrsa -out sample.key ...
Dmitry's user avatar
  • 117
1 vote
1 answer
239 views

DKIM aligned but not authenticated for mailboxes moved to Exchange Online in a hybrid configuration

For mailboxes migrated to our tenant, they have this in the received message header of external recipients after migration: arc=fail (body hash mismatch); SPF/DKIM/DMARC all pass using the records ...
Srfndoc's user avatar
  • 21
0 votes
2 answers
95 views

Should we add SPF records of popular email providers?

DMARC is reporting that a small fraction of our emails originate from google, microsoft, and some other providers. DMARC is also reporting that a good chunk of those emails fail both SPF and DKIM, and ...
rvh's user avatar
  • 109
0 votes
0 answers
153 views

DMARC and Postfix delivery reports

I successfully set up DMARC, DKIM and SPF for my mailserver's domain, but delivery reports created by Postfix fail the DKIM/SPF tests. The headers of regular messages (sent via my mailserver) look ...
janeden's user avatar
  • 267
0 votes
1 answer
341 views

DKIM signing – duplicate header signing in DKIM-Signature

My e-mail messages are DKIM signed but I noticed that the DKIM-Signature header contains duplicated header indicators like: h=from:from:subject:subject:date:date:message-id:message-id:to:to: […] and ...
silverdr's user avatar
  • 101
0 votes
2 answers
132 views

A Non-MX mail server + Google Workspace, is this viable?

I have a domain (example.com) configured for sending and receiving mail using Google Workspace. I need to launch additionally a separate (own) mail server. Switching completely to the new server is ...
x-yuri's user avatar
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0 votes
1 answer
651 views

Should HELO, MAILFROM and From use the same domain?

I configured a mail server a couple of times before and I believe back then I thought that the answer is "yes." But I'm about to configure another one, and it seems that I was wrong. Let's ...
x-yuri's user avatar
  • 2,298
1 vote
0 answers
469 views

DKIM Signature Body Hash Verified to Office 365

I am checking the email header in https://mxtoolbox.com and getting the error DKIM Signature Body Hash Verified. Problem only occurs when sending emails to other Office 365 accounts. The same email ...
supmethods's user avatar
3 votes
1 answer
397 views

How to make postfix sign non-delivery notifications with DKIM?

I have set up my "postfix" server to sign outgoing messages with DKIM and verified that it works correctly for SMTP users using authentication. However, "non-delivery notifications"...
mist's user avatar
  • 33
0 votes
0 answers
40 views

Getting Spoofed - DMARC , DKIM and SPF are properly setup (AFIK)

I have been testing my DMARC policy for some weeks and I ran into this issue. Background: SPF - setup and working DKIM - set up and working (AFIK) DMARC - set up and working - looking for alignments ...
mat's user avatar
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0 votes
2 answers
166 views

What is the behavior of a DNS resolver if one authoritative name server does not have particular record but another one does

Say I have sent a query for TXT record for m1._domainkey.amazon.com nslookup -q=txt m1._domainkey.amazon.com Say the authoritative nameservers for amazon.com are amazon.com nameserver = ns1.amzndns....
Hassu's user avatar
  • 19
0 votes
0 answers
142 views

Config Wizard error in Rspamd on dkim step in Debian Bullseye

Using fresh Debian 11.7 installation I’m trying to setup RSpamd using configwizard, but in the last step of building the private key I got the following error: Do you want to create privkey /var/lib/...
MaxMil's user avatar
  • 101
1 vote
1 answer
252 views

Exim false negative on DKIM verification

My mailserver using exim4 has an ACL to check DKIM signatures. It accepts everything but it logs failures and writes a header with the results. I'm sending mail from another server which I believe is ...
artfulrobot's user avatar
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1 vote
1 answer
4k views

How to correctly split a DKIM txt dns entry?

many questions here on spliting DKIM txt records, but my dns provider only allows 255 chars for each key. no fancy way to enter multiple values like the other platforms mentioned all the other ...
gcb's user avatar
  • 82
0 votes
1 answer
692 views

EXIM4: Signing Emails with DKIM

I really am banging my head against the wall with this one. I have tried for serveral days to get dkim signing to work on outbound emails from a server running on Debian 12, exim4 version 4.96, but to ...
joe.mse's user avatar
1 vote
3 answers
91 views

What is the difference between a query for a TXT record and a query for a TXT record against a particular name server?

For the purpose of implementing an email server, I want to be able to look up a domain's DKIM record. What is the difference between these two sets of DNS queries? Which should I choose to implement ...
Hassu's user avatar
  • 19
0 votes
1 answer
651 views

Do spaces in DKIM records matter?

I'm trying to get BIND show my DKIM exactly like it was generated but it seems like the " sign is messing up the results for dig. If I don't insert the public key within "" then dig ...
SamTzu's user avatar
  • 33
0 votes
1 answer
1k views

Postfix - can't send emails to gmail addresses via terminal

I have the following errors when trying to send emails to gmail addresses via my terminal: sudo tail /var/log/mail.log Jul 19 13:19:44 ubuntu-4gb-fsn1-1 postfix/cleanup[5780]: B4B8C5F4A3: message-id=&...
Run's user avatar
  • 101
0 votes
1 answer
84 views

OpenDkim - PHPMailer - Failure OpenDkim

my dkim configuration was working just fine. Im working with an email marketing app, pretty simple, normally i used to send the campaign with a Sender ID that is my domain company, and for the From ...
Luis Alfredo Serrano Díaz's user avatar
0 votes
1 answer
130 views

Mail server running on a subdomain - how could email acceptance by other servers be influenced by dns records for different ips?

I started to run a self-hosted mail server which I want to be reachable via a subdomain only. I have an A record for mail.sub.domain.tld and an MX record for sub.domain.tld /edit: which points to mail....
cssdev's user avatar
  • 23
0 votes
1 answer
686 views

DKIM Postfix message not signed for outgoing mail

I've been working on setting up SPF, DKIM, and DMARC for the past couple weeks. All is now successfully working, except that I cannot get my outgoing mail to be DKIM signed. Debian 11 is the OS, ...
Dylan Danger's user avatar
0 votes
2 answers
2k views

How to setup DMARC for both AWS SES and Office 365

I'm trying to get DMARC working for the emails I send via Office 365 as well as Amazon SES. It's working for Office 365 because I setup the SPF and DKIM records in my DNS but it's failing for the ...
Russell G's user avatar
  • 153
0 votes
0 answers
255 views

Error Configuring DKIM on Bind BIND 9.9.4-RedHat-9.9.4-61.el7_5.1 (Extended Support Version)

I'm trying to configure a DKIM record on my DNS Server running BIND 9.9.4-RedHat-9.9.4-61.el7_5.1 (Extended Support Version), but I'm getting the following error: 10:36:40 ns1 named[14663]: db.domain....
jfcarvalho's user avatar
1 vote
2 answers
2k views

Why does DMARC fail for forwarded emails from this particular domain when it passes for all other domains?

I run a virtual mail server that forwards emails to my domain to a Gmail address, and I use PostSRSd to rewrite the addresses. For example, if someone sends an email to [email protected], my mail ...
John Doe's user avatar
  • 365
0 votes
1 answer
470 views

DKIM on GoDaddy shared hosting [closed]

I'd like to setup a DKIM record on GoDaddy shared hosting with cPanel (I don't want to move the DNS server). Normally cPanel makes creating DKIM records trivial, but in cPanel on GoDaddy shared plan ...
Nick's user avatar
  • 11
-4 votes
1 answer
237 views

OVH DKIM Record Not Found

I set up a DKIM Record on my OVH VPS recently. The ultimate record generated is as follows (public key overwritten): v=DKIM1;g=*;h=sha256;k=rsa;s=email;p=...
Trunk's user avatar
  • 101
0 votes
1 answer
1k views

DKIM fails when users forward Hotmail to Gmail

I use AWS SES for sending mail and CloudFlare for DNS. I set up DKIM following this tutorial. It works well. When a user provides a hotmail.com address and forwards it to Gmail, I receive an email ...
emonigma's user avatar
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