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 ...

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1answer
265 views

Have Postfix/OpenDKIM sign only authenticated and local origins

I'm signing email just fine, but I don't want to sign relayed email when the "From" address is one of the domains I'm signing. What's the right way to configure Postfix/OpenDKIM to sign only from ...
0
votes
2answers
279 views

Error sending emails from a mail server relay type falling into the spam folder (using postfix)

Here I show one of the emails that come to Yahoo, which are falling directly into SPAM folder. The SPF goes smoothly, the DKIM passes without problem, even DMARK passes without problem, but just keep ...
4
votes
3answers
473 views

Will mailing lists “break” if SPF is too restrictive?

I have recently configured my own mail server (Linux-based postfix + dovecot scenario). This is just for personal use - I have no bulk mail going out, no automatically generated mail outbound from the ...
3
votes
3answers
314 views

Is there anything bad about DKIM-signing mail without the key in DNS?

At a site that I manage, we send out emails for many customer domains. Some of them have our DKIM key in DNS, some don't. From what I can tell: Signature verification failure does not force ...
0
votes
0answers
37 views

Sign with one DKIM key for all subdomains [duplicate]

I've set up DKIM key for primary domain as per this tutorial: http://askubuntu.com/questions/134725/setup-dkim-domainkeys-for-ubuntu-postfix-and-mailman Can I use the same key to sign for subdomains ...
2
votes
1answer
2k views

DMARC is blocking email that seems like it should be allowed

This is the DMARC record we have set v=DMARC1; p=reject; rua=mailto:[redacted]@coinbase.com; adkim=r; aspf=s So we are rejecting any not match with SPF strictly, and DKIM is relaxed. Here is the ...
2
votes
2answers
1k views

Postfix sends email to spam (gmail, hotmail)

I recently installed a postfix + dovecot + dkim multi domain, multi user, multi alias mail server on my debian squeeze system. Everything works except for one big issue that basically makes the whole ...
2
votes
3answers
386 views

Is it safe to use port25 to generate DKIM key

I found this site. But if I use it, doesn't it mean that port25.com would know and be able to use my private key?
2
votes
1answer
315 views

How to prevent emails from my domain through mailing lists to be rejected due to DMARC

I operate my own mail server at speedofsoundgaming.com and mwtd.net. I recently added a DMARC record to my domain to help prevent spam, and once seeing that things seemed to be working, upped the ...
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votes
2answers
743 views

DKIM do I need to allow port 8891 on my firewall? [closed]

I'm trying to set up dkim on my server so my emails are less likely to end up in my customers' spam. Quick question: does port 8891 need to be opened? I'm using ufw. Many thanks in advance,
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vote
5answers
842 views

What domain name should appear in a DKIM signature?

I followed these instructions to setup OpenDKIM with Postfix, and it works as advertised. My outgoing mails have the DKIM-Signature header added, for example: DKIM-Signature: v=1; a=rsa-sha256; ...
6
votes
1answer
3k views

Exim doesn't want to do DKIM signing correctly

I'm using exim 4.82 on Debian sid. I've followed several tutorials on how to configure exim to sign outgoing emails, but it seems like something is not behaving as it should be. My diagnosis is that ...
0
votes
1answer
62 views

Using DKIM in my server for multiple domains (websites)

As I couldn't find this exact tutorial in Stack, I share my findings with al of you. I always get things solved thanks to this comunity. Thanks! Original question: I've read the tutorial posted by ...
1
vote
0answers
137 views

Postfix configuration with DKIM to send mail from multiple domains [duplicate]

My current setup is a Postfix installation configured with DKIM on a server with hostname prod01.example.com The server is used to send out mail on the form webshop@example.com, ...
6
votes
1answer
5k views

DKIM and SPF for a subdomain

I manage a VPS on Linode accessed through subdomain.example.com and I need to send email from this subdomain. I can't set any TXT records in Linode DNS manager because the name servers for example.com ...
1
vote
2answers
38 views

Precedence/co-existence of SPF and DKIM

Is co-existence of SPF and DKIM specified somewhere (assuming the absence of DMARC)? I want to put only my own IPs in the SPF and let 3rd parties send mail on behalf of my domain using DKIM. What ...
1
vote
1answer
127 views

spf and dkim records in the same dns zone file

I am trying to set up a mail server which will sign outgoing messages with a dkim signature. Part of that process is to set up a dns record for my senders domain with the public key of the key used ...
1
vote
2answers
369 views

SPF/DKIM Configuration for usage with critsend

I am currently facing the following issue: I have configured a domain of mine to be used with the Critsend mailing service. Their recommended configuration for both SPF and DKIM was implemented on ...
0
votes
2answers
336 views

Email flagged as spam or rejected by recipient mail server

I have configured SMTP service on a windows 2008 server. All the emails sent by the SMTP service are flagged as spam or they are rejected by the recipient of the email. In the header of the email I ...
3
votes
2answers
356 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 ...
0
votes
2answers
46 views

Marking emails with DKIM - safe?

Im running an email server as part of a research study. We have subjects connecting and sending email from a variety of clients. One function of this server is to communicate with said subjects - ...
0
votes
1answer
475 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 ...
2
votes
1answer
4k views

Publishing long domain key records in bind9

I am setting up a mail system based on exim4. This system implements DKIM signing and checking (among other things). Signing seems to work without problems but checking doesn't work and exim4 ...
0
votes
1answer
252 views

opendkim requires libcrypto [duplicate]

I am trying to install opendkim. For that, I used rpm to install epel, then did yum install opendkim. However, I get the following dependency errors: Error: Package: opendkim-2.9.0-2.el6.x86_64 ...
3
votes
3answers
7k views

no signing table match in OpenDKIM

I have OpenDKIM installed on CentOS. I am using postfix as MTA and dovecot for IMAP/POP3. Now the problem is am trying to setup DKIM for my domain. The mails are send from a sub domain ...
2
votes
1answer
121 views

When creating DomainKeys does it matter if I use o=~ or o=-?

I used this utility to create my DKIM key (1024 bit size), since Gmail has been blocking us (we had an old joomla install exploited, was around before me). And I got this back: Your Selector Record: ...
3
votes
3answers
7k views

Domain Key not showing up in DNS query

*SOLVED - See bottom of this post * So problem here is that I have been trying to set up a domain key for several days. I've done it successfully in the past, but I just can't get it to work this ...
2
votes
2answers
2k views

opendkim incoming not verified

I've installed opendkim with postfix on Debian Wheezy. Outgoing mail is getting DKIM signatures. The smtpd and non-smtpd milter spec is the same. Incoming mail seems not to be verified - in a ...
0
votes
1answer
111 views

Will setting up DKIM on Google Apps interfere with mail sent from the web server using the same domain name

I would like to set up DKIM on my domain for messages sent using Google Apps. I understand how to do this but I am concerned that if I have a DKIM DNS record for the domain, messages sent from the ...
0
votes
1answer
78 views

What to look for when using a 3rd party Email Enrichment Service - to secure our emails? [closed]

Our marketing team wants to use a 3rd party Email Enrichment Service. I want to try and tackle this, as I don't like the idea that my mail will go through a certified service and exposed. I know ...
1
vote
1answer
2k views

How to correctly configure postfix and opendkim and let receiving server know all details mailed-by signed-by?

What I am trying to achieve - Bottomline: mails to go in inbox rather spam folder. I have a server which is running postfix (mail server) and I have 3 domains. Mail server is used for both incoming ...
1
vote
1answer
203 views

Whose DKIM signature to use, my own or Amazon SES'?

I have OpenDKIM properly set up to sign emails from my domain such that when sent through Amazon SES, Yahoo Mail shows dkim=pass. Given I got the infrastructure working, is there any benefit to ...
0
votes
1answer
31 views

Domain Key Entries

More BIND DNS questions. OK, my changes the the zone files are no propagating out. Now I'm having a problem with the domain key entries I'm trying to create. I'm starting by trying to set the domain ...
1
vote
0answers
521 views

postfix opendkim DKIM-Signature and Domainkey-Signature

Running postfix on CentOS 6 as an edge relay for a while now, so all our outgoing mail is routed through one point with opendkim signing the mail. This works great. I was originally using ...
1
vote
1answer
2k views

Configuring SPF, DKIM, Reverse DNS for VPS sending email through Google Apps SMTP servers

Today we realized that all of our emails being sent to email addresses of the type <username>@corporatedomain.com were getting rejected. I don't know who is hosting the email for ...
7
votes
4answers
2k views

Why does my mail get marked as spam?

I Have the server "afspraakmanager.be". It matches everything not to be a spam server.(it isn't by the way): it has reverse dns, spf,dkim,... . But hotmail marks it as spam. I think the problem is ...
0
votes
1answer
850 views

OpenDKIM - verifying mail forwarded by mailing lists

I'm using OpenDKIM for verifying signed mails that are incoming to my mail server and use it as a spam addon (if dkim is broken, mail lands in Junk). However, I'm getting lot of false-positives with ...
1
vote
0answers
303 views

Postfix + Amavisd-new as smtp-proxy (pre-queue) for inbound only, postqueue for outbound?

I am in the planning phase of building a mailserver with the following requirements relevant to my question: Use postfix, virtual users (two virtual domains) Must filter pre-queue to reject ...
6
votes
3answers
8k views

Why is my email failing Gmail's DKIM test?

I have a message that was rejected by Gmail, I don't know why. It passes SPF. We aren't using DKIM. Do I need to set up DKIM? I am in control of "example.com". Our mail server is "server.example.com" ...
6
votes
2answers
419 views

Designating A DKIM Signer Other Than The “From” Domain

A few months ago, I implemented SPF/DKIM/DMARC for my three-person company. After a trial period, I switched our DMARC to "p=reject", so that emails are rejected if they fail SPF/DKIM. Generally, it ...
1
vote
1answer
190 views

Mails marked as spam in gmail for some accounts

I have a couple of domains running on my VPS with VirtualMin. I have DKIM enabled, reverse DNS is setup and SPF records are added by Virtualmin. Now I have a main account (admin) which I can easily ...
0
votes
2answers
38 views

Required entries in DNS records [closed]

Writing a brief best practices technical document for in house. A Records for hostname / IP mapping (blank).mydomain.com www.mydomain.com *.mydomain.com -can also add subdomain, ftp, cpanel, etc ...
6
votes
1answer
1k 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 ...
0
votes
1answer
696 views

Email authentication without modifying DNS records

Can someone explain how Mailchimp does email authentication without user having to update SPF or DKIM records? Quote from Mailchimp: When you use MailChimp's authentication, campaigns will pass ...
0
votes
1answer
824 views

dkim-milter appears not to be signing my emails correctly

I have a VPS that I had a fresh install of CentOS 6 on it and then I installed virtualmin on it and we've been great for a few months. I've been hosting a handful of domains from there and on one of ...
0
votes
1answer
641 views

unknown configuration line “INPUT_MAIL_FILTER(dkim-milter, S=inet:8891@localhost)”

I followed a tutorial using the socket connection dkim-milter to sign my outgoing mail. I did it and the conf file loaded fine. But I discovered that my mail were not signed. I found many other ...
0
votes
1answer
701 views

Dkim DNS Setup: dig +trace finds the key, dig notrace doesn't

i'm setting up DKIM for my domain to sign outgoing mails. I've got some issues on DNS configuration, because DNS configuration is mixed between external DNS (hosting) and a cloud server, which sends ...
0
votes
1answer
813 views

How to write DKIM TXT DNS Record in GoDaddy?

I am trying to understand how I should write my DKIM key in GoDaddy. What I wrote in the picture is my guess but I will then add my DKIM Key to sendmail and if I'm note sure this one is right I'll ...
0
votes
1answer
103 views

SPF, Sender ID and DKIM signing - Does Sender ID need to be configured if DKIM signing in place?

While learning about SPF, Sender ID and DKIM siging, it seems that Sender ID and DKIM exist to solve similar problems. In addition, Sender ID is discussed in a fairly unflattering light on several of ...
1
vote
1answer
325 views

DKIM Signing not working, amavisd indicates that is passes

amavisd-new testkeys indicates a pass, but mailtest@unlocktheinbox.com says that my DKIM signature could not be found? Anyone ran into this before? Anyone got any easy ways to set up DKIM signing? ...