DKIM Keys

eMill can sign outgoing messages using DKIM signature. Different keys can be used to sign messages regarding the sender email address or the sender domain.

• From the Tools/Options, menu, click on the DKIM Keys tab:

Click the Add button to enter a new DKIM key, the Modify button to modifiy a selected DKIM key, or the Remove button the remove a selected DKIM key.

DKIM key dialog

This dialog let you configure a new DKIM key or modifying an existing DKIM key.

• Enabled: speficies if the DKIM key can be used.
• Selector: speficies the selector name associated with the DKIM key. The selector determines with the domain the DNS record name that contains the public key. This field is mandatory.
• Domain: speficies the signing domain associated with the DKIM key. The domain determines with the selector the DNS record name that contains the public key. This field is mandatory.
• Identity: specifies the identity email address of the signer. The identity address must belong to the signing Domain. This field is optional.
• Private Key: specifies the RSA private key used to sign messages.
• Generate: creates a new 1024 bits RSA private key. This should be used only with new DKIM keys.
• Restrictions: speficies if the key should be used to sign messages from a specific sender or a specific sender domain. When eMill searches for a key to sign messages, it first searches in the address restricted keys, then in domain restricted keys and finally in no restricted keys. There should not be two keys with the same restriction.
• DNS associated record name: informational field automatically generated that contains the name of the associated DNS record associated with the DKIM key.
• DNS associated record data: example of data the DNS record associated with the DKIM key must contain. This data contains the public key.
• Check DNS: performs a DNS lookup to check the validity of the DNS record associated with the DKIM key. The public key present in the DNS record is compared with the public RSA public key associated with the DKIM Private Key. A message box will display the result of the validity test.