Hmailserver dkim

DKIM (DomainKeys Identified Mail) is a technique used to authenticate the sender of an email message. It involves adding a digital signature to the email message that is verified by the recipient's mail server. Here's how to set up DKIM on hMailServer:

Prerequisites:

• hMailServer version 5.6 or later
• A domain name (e.g., example.com) that you want to use for DKIM
• A TXT record set up in your DNS for the domain (see below)

Step 1: Create a public/private key pair

You can use a tool like OpenSSL to generate a public/private key pair. For example:

openssl genrsa -out private.key 1024
openssl rsa -pubout -in private.key -out public.key

This will generate a 1024-bit RSA key pair. You can use a stronger key size if you prefer.

Step 2: Configure hMailServer

In hMailServer, go to the "Settings" > "Protocols" > "SMTP" section. Click on the "Advanced" tab and scroll down to the "DKIM" section.

• Set "DKIM enabled" to "Yes"
• Set "DKIM selector" to a unique value (e.g., "dkim")
• Set "DKIM key" to the contents of the public key file (public.key)
• Set "DKIM domain" to your domain name (e.g., example.com)

Step 3: Create a TXT record in your DNS

You need to create a TXT record in your DNS that contains the DKIM public key. The format of the TXT record is:

_kim.example.com. IN TXT "v=DKIM1; k=rsa; p=MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQC..."

Replace _kim with the DKIM selector you chose in Step 2, and example.com with your domain name. The p parameter contains the public key.

Step 4: Test your DKIM setup

Use a tool like dig or nslookup to verify that the TXT record is correctly set up in your DNS:

dig _kim.example.com. TXT

This should return the DKIM public key.

Step 5: Configure your email clients

To use DKIM, your email clients need to be configured to use the DKIM signature. This may require updating your email client's configuration files or using a plugin.

Troubleshooting tips:

• Make sure that the TXT record is correctly set up in your DNS and that the public key is correctly configured in hMailServer.
• Check the hMailServer logs for any errors related to DKIM.
• Use a tool like opendkim to test your DKIM setup and verify that the signatures are being generated correctly.

By following these steps, you should be able to set up DKIM on hMailServer and start using it to authenticate your email messages.