Enabling DKIM for a domain attaches a special header to every email sent from the domain. This header contains a cryptographic private key. The recipient mail servers use a public key to verify that an email was indeed sent from the domain and no one tampered with the email content in transit. Emails that do not have the header will be detected as not authentic.

You can enable DKIM email signing for domains that use the Plesk DNS server and those that use an external DNS server.

You enable DKIM signing for each individual domain.

To enable DKIM signing of outgoing mail for a domain:

  1. Go to Websites & Domains > your domain > the 「Mail」 tab > Mail Settings.

  2. Select the 「Use DKIM spam protection system to sign outgoing email messages」 checkbox and then click Apply.

    If you use the Plesk DNS server, you have enabled DKIM for the domain. Plesk adds the following two records to the DNS zone of the domain (example.com stands for your domain name):

    • default._domainkey.example.com contains the public part of the generated key.
    • _ domainkey.example.com contains the DKIM policy. You can edit this policy.

    If you use an external DNS server, you have one more step left. Plesk cannot add the DNS records to the external DNS server. Add them yourself using a hint from Plesk.

  3. Click 「How to configure external DNS」 to open the hint. Copy two DNS records you see there and add them to the DNS server.

備註: If you have domain aliases you use to send mail, add the DKIM DNS records for them as well. Use the same records as for the main domain but with the domain alias name.

image DKIM external DNS

發送郵件的 SPF 和 DMARC 策略

除了 DKIM,Plesk 還支援將 SPFDMARC 策略用於發送郵件。DMARC 執行策略以根據 DKIM 和 SPF 檢查的結果來處理郵件資訊。默認,DMARC 使用常規策略,而沒有通過檢查的資訊不會被刪除。您可以使用更為嚴格的策略。例如,您可以指定在資訊同時通過 SPF 和 DKIM 檢查的情況下才能被收件人郵件伺服器接受。

You can change the SPF and DMARC policies for your domain in the domain’s DNS settings.

若要為您的域名設定 DMARC 或 SPF 策略,請如下操作:

進入 網站與域名 > 導向某個域名> DNS 設定 編輯與SPF 或 DMARC相關的 DNS 記錄。例如,該記錄包含了預設的DMARC 策略:

_dmarc.<your domain>.    TXT    v=DMARC1; p=none

See more information on DMARC and SPF (including policy notations).