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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 keeps returning “no key for signature”

EDIT Oh I forgot to mention... I'm using this hmailserver guide to do my signing... Question I've seen this answer and triple checked the keys and setup on my client's domain. So the information I'...
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1answer
51 views

dkim=temperror (no key for signature) then dkim=pass

I published a DKIM record for my niceoldteacher.com domain that is hosted by fatcow.com and sent an email to one of my gmail accounts to see if DKIM was working. Although the header summary for the ...
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1answer
2k views

DKIM header exists but signature is not valid

UPDATE Now the validator at mail-tester.com says the DKIM signature is fine. On the other hand the isnotspam.com still doesn't seem to like it. I assume it is working fine now. Also gmail accepts ...
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1answer
25 views

OpenDKIM / Postfix sign console-sent mail, but not from a mail client / SMTP

I have Postfix running on a Debian 9 machine, and installed opendkim (both from the Debian repositories). The milter socket/connection is inet:localhost:8892, and the iptables firewall allows that ...
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14 views

DKIM “default” selector

I often see DKIM configuration guides using default as the selector. Is this a special selector or it is just a convention to use this if you only have one mail server? In other words, if I use the ...
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1answer
23 views

8bit to Quoted-Printable encoding in Exim

Is it at all possible, and how, to configure the Exim4 mail server to convert outgoing messages (or message parts) from 8bit encoding to Quoted-Printable (or Base64, although I'd prefer QP) before ...
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12 views

Why DKIM validation fails for yahoo, but pass for others?

Why does the DKIM validation for my mailserver fail for Yahoo but nor for others ? I saw this question, but I don't think it's the same issue and the answer was not helpful to me. MxToolbox gives no ...
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2k views

Should DKIM selector names be unguessable?

The M³WAAG DKIM Key Rotation Best Practices document (pdf) recommends a "sufficiently" random DKIM selector name so that it cannot be guessed by browsing the DNS. A literal quotation: 4.3 Key ...
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1answer
47 views

Debug DKIM on MacOS X

I am setting up DKIM on MacOS X/Server using Amavis-new. Everything seems ok, by when I try to test it using sudo -u _amavisd -H amavisd -c /Library/Server/Mail/Config/amavisd/amavisd.conf testkeys ...
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30 views

DMARC and DKIM Authentication-Results for forwarded mails with multiple DKIM signatures

I am kinda lost in here, so please, bear with me. I have trouble with getting DMARC implementation right with opendmarc. When there is forwarded mail that is correctly signed by original sender, dmarc ...
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1answer
194 views

Outgoing email marked as spam. Can you tell what is wrong from email header?

I have a send-only server using postfix. The outgoing email goes to Yahoo's spam folder. It is a test email, the content is very short. I attach the header below. The SPF, DKIM all looks good. Can you ...
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1answer
22 views

DKIM on aliased domains with rspamd and postfix

I'm having trouble DKIM signing my outgoing emails when they're sent from an alias domain. That is, when I'm authenticated with user@domain1.com sending as user@domain1.com or somebodyelse@domain1.com ...
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1answer
2k views

dkim verification keeps failing bad signature

My DKIM verification keeps failing, and I can't figure out why. It's signed though, but wrong. When I check domain and selector it turns out as valid, so problem is with signing. Here is a dump of ...
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136 views

RSPAMD + DKIM Signing: How to be able to use a single DKIM Key for multiple domains?

I was able to setup a Single DKIM Key for multiple domains with OPENDKIM by using their KeyTables and SigningTable. But since the company started to use RSPAMD, I could not use OPENDKIM along with ...
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1answer
982 views

DKIM signature and hmailserver - Your DKIM signature is not valid

I'm trying to get DKIM working on a domain using hmailserver as the mailserver, but I keep on getting Your DKIM signature is not valid This is from www.mail-tester.com The DKIM signature of your ...
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2answers
88 views

Setting up exchange 2019 with DKIM on Azure VM

I wanted to setup and configure my first exchange server on an Azure VM. I presume I need to forward the MX records for my domain to the Azure VM? Do I need to setup Active Directory on this new VM i....
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2answers
595 views

SPF and DKIM configuration Ubuntu 18.04 fails

I have been following this tutorial from DigitalOcean. I have followed every detail but nothing seems to work as expected. Assuming that my FQDN is the following: mydomain.com. Here are my details: ...
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75 views

DKIM - many subdomains without multiple txt records

I've been having trouble with opendkim, figuring out how to best create records for multiple subdomains. I've tried using wildcards to cover all of the subdomains and wasn't able to get it working. I ...
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1answer
978 views

How sendgrid assigning its DKIM keys when we send email from application

I was exploring about DKIM. I read an email which was sent via sendgrid and with application from remote server. My question is , how can assign the DKIM key of own server if sender id do not exist in ...
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1answer
21 views

OpenDKIM signing conditions

Is it possible to use conditions for signing outgoing messages with OpenDKIM? It should only sign outgoing messages if the selector exists in DNS.
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5answers
31k views

How do I enter a strong (long) DKIM key into DNS?

I'm trying to enter a 4028 bit DKIM key into DNS and it seems that I'm exceeding both the UDP 512 byte limit and also the maximum record size for a TXT record. How does someone properly create a ...
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1answer
1k views

Exchange mailbox forwarding - emails fail dkim body hash

Exchange is modifying emails before forwarding them out to an external Google Apps account. I'm hoping to find a way to fix this. Here's some more detail: Using Exchange 2010 SP3 Version 14.3.123.4 ...
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1answer
1k views

message headers say dkim = fail, stats say = PASSED. why the conflict, and how to fix?

In some-not-all received emails -- notably ONLY those sent via 'bulk' services -- I get a DKIM fail: "signature verification failed". Here's one example: Received message headers DKIM-Filter: ...
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1answer
54 views

Dkim record fails - A public-key (p=) is required

I setup dkim record using following tutorial. But when I check the mx records using googleapps toolbox and dkimcore cheking tool it gives error google says dkim is not setup, dkimcore says A public-...
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1answer
1k views

Hotmail/Outlook.com DKIM failure when signing with different domain - header.d ignored

We (sender.org) provide a mail server for a client (example.org) and sign outgoing messages with our private DKIM key (we cannot change the signing domain to the client's domain). Return-Path: ...
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1answer
548 views

Valid DKIM but “body hash did not verify” error on Outlook / Hotmail / Live?

Why do I get dkim=fail (body hash did not verify) on Outlook / Hotmail / Live when I have a valid DKIM setup in place? I've made sure that my SPF, DKIM, DMARC records are set up correctly and the ...
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2answers
9k views

how to configuration dkim on exchange email server

Mails sent from our internal email server to public servers such as Gmail, Yahoo and all other external organizations are delivering to spam. We currently use exchange server, in order to tackle above ...
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14 views

Adding AWS SES DKIM for domain using G Suite

My company has a domain acme.com with multiple subdomains running various AWS servers which are accessible via subdomains like client1.acme.com and we're also using G Suite for email. I'd like to ...
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0answers
35 views

If mail from “me” isn't DKIM signed, reject it

I am getting DMARC reports stating that an unauthorized IP is claiming to be me (our domain is in the headers). Looking at this section of the DMARC report, it occurs to me that I should be able to ...
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1answer
60 views

How can I create a DKIM Record?

I am not sure how to add a DKIM Record to my mails/server. Do I only have to generate it from here -> https://dkimcore.org/tools/keys.html and add it to my DNS?
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1answer
45 views

I have set the DKIM record but my emails is not signed?

I have set the DKIM record on my DNS server provider (Cloudflare) and i tested it using different online tools which all says that my dkim record is valid but all my messages i sent dont have DKIm ...
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2answers
8k views

postfix: connect to Milter service inet:127.0.0.1:8891: Connection refused

I noticed that there is a error with milter if I type service postfix status : Jul 01 17:39:01 mail postfix/cleanup[13921]: warning: connect to Milter service inet:127.0.0.1:8891: Connection refused ...
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3answers
1k views

Why is my opendmarc failing pretty much everything that comes through?

I have this domain for which I set up SPF, DKIM, and DMARC stuff. Let's pretend the domain is example.com which has the following entries in its DNS zone: example.com. 600 IN MX ...
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1answer
24 views

SPF and DMARC protection

Today while working at my company, we saw allot of automatic reply emails coming into one of our group inboxes (i.e. info@company.com). We suspect that this email address is being used in a phishing ...
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18 views

Will a single domain without DKIM affect mailserver IP reputation?

Just something I was curious about with mailserver reputation. Let's say I have a mailserver at IP 1.2.3.4 that handles emails for a couple of domains. If I have DKIM installed for some of these ...
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3answers
3k views

Exim4 does not add DKIM signature

Have spent 2 days trying to tell Exim to add DKIM signatures on my Debian8 server. No success. Have read many how-tos, forums but none of possible solutions wotk on my server. Have generated the keys:...
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2answers
99 views

DKIM in Exchange Server 2010

I need to generate DKIM public/private keys for Exchange Server 2010. https://www.emailarchitect.net/domainkeys/kb/dkim_exchange_2007_2010_2013.aspx I have run the DKIM Installer but it was hanging ...
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2answers
586 views

DMARC and DKIM alignment with multiple DKIM signatures

If an email contains multiple DKIM signatures as it's forwarded, how does DMARC process the DKIM alignment check? Does ANY passing DKIM signature d= parameter have to match Header From? or Does the ...
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2answers
60 views

SPF and DMARC - is spf policy used?

I understand how SPF is involved with DMARC alignment, but one thing I can't get clear: is the SPF policy (-all or ~all) used in DMARC? Or does DMARC merely use the IP ranges? The issue is, that as ...
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3answers
16k views

SPF vs. DKIM - The exact use cases and differences

I'm sorry for the vague title. I don't fully understand why SPF and DKIM should be used together. First: SPF can pass where it should fail if the sender or DNS is "spoofed" and it can fail where it ...
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2answers
1k views

Route53 DNS and DKIM/TXT

I've been trying to set an openDKIM public key as a TXT record within the Route53 hosted zone for my domain. The record is mail._domainkey .zewtie.io but, however I enter the public key in the ...
9
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2answers
906 views

Exim 4.71 does not add DKIM signature to outgoing emails

I am trying to add DKIM to my domain, I have created a key, added the following to /etc/exim4/conf.d/transport/30_exim4_config_remote_smtp: dkim_domain = mydomain.com dkim_selector = mail1 ...
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1answer
152 views

Emails go to spam ( Reverse DNS is set , DKIM pass , SPF pass , DMARC pass ) [duplicate]

It's been now 3 days that I am struggling with configuring my emails to go to the inbox. I have a VPS server at OVH and a domain name. I have configured everything in virtualmin with OpenDKIM and ...
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1answer
48 views

DKIM : Which domain is considered?

DKIM verifies the domain of an e-mail sender, but... What "domain" does it check? The "domain" of the MAILFROM field of the SMTP envelope ? The "domain" of the FROM header of the message ? The "...
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1answer
2k views

opendkim no signing table match for no signature data

I got an error when I try to install and config opendkim : no signing table match for 'contact@domain.com' no signature data opendkim.conf : # This is a basic configuration that can easily be ...
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1answer
49 views

where should i add dkim records when using custom name servers?

I have recently setup mail server on ubuntu14.04 using postfix, dovecot. I am very confused about adding dkim records. Every tutorial i have followed is saying i should add dkim at domain registrar ...
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2answers
622 views

When DKIM is installed, will I still be able to send email for my domain from gmail?

Let's say I own example.com, that I install and configure dkim on my server (apt-get install opendkim opendkim-tools, etc.), and that I add the relevant public key to the domain's DNS records. Then ...
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0answers
145 views

opendkim on lokal net not working

I have a assignment in school to setup bind9, postfix, spf, dkim and dovecot on the same machine for the address mcduckcorp.duckburg.cali on a Debian 9 OS. I have managed to setup bind9, postfix and ...
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1answer
109 views

DKIM public key & DKIM from DNS are the same but don't match because of spacing

Please take a look at this picture of mail-tester.com saying that Your DKIM signature is not valid. As you can see, the DKIM signature and public key are identical in term of text (characters) but ...
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1answer
345 views

SPF,DKIM Failure and outcome

I have been doing a lot of reading around SPF, DKIM and DMARC and i think i have digested most of the information and how all three work in the email world. However one question i couldn't find is, ...