A mail domain is a set of mailboxes associated with a single domain name. Every mailbox has its email address in the format "<mailbox name>@<domain name>". E.g., "mail@example.com".

Perform the following steps to add a mail domain in ISPmanager:

  1. Go to Domains→ Mail domains → Add.
  2. Enter the Name of the mail domain that you want to add.

  3. Select the Owner of this mail domain.
  4. Select an IP address to send emails. Select "receive automatically" to assign a free IP address to the newly created mail domain.


    "<mail domain name>:<IP address>" is added into /etc/exim/domainips.

  5. Select the Default action that is needed when an e-mail is received stating that a mailbox does not exist:

    • Reply error — the sender will be notified that the mailbox does not exist (recommended);
    • Ignore and drop — if the mailbox does not exist, the user will not receive delivery failure reports. The mail server will not accept mail and will delete it;
    • Redirect to domain — if the mailbox does not exist, the user will be prompted for an alternative mail domain specified in the field  Redirect to;


      The redirect won't be applied if you enter an email alias in the field Redirect to.

    • Redirect to domain  — the mail server will try to find the mailbox on the mail domain specified in the field  Redirect to.

    "<mail domain name>:<mail domain name>:<redirect address>:no" will be added to /etc/exim/domains.

    <redirect address> is an empty value if the default action is "Reply error"; "/dev/null" if the default action is "Ignore and drop"; an email address or domain name if the default value is "Redirect to email" or "Redirect to domain".

  6. Enable additional options. They are available only if the corresponding module is installed. Please refer to the article Install a mail serverfor more details.
    • Enable Greylisting — Greylisting is a method of defending e-mail users against spam that temporarily rejects any email from a sender it does not recognize. Select this check box to enable  Greylisting for the domain's mailboxes. Otherwise the mail domain is added into /<postfix directory>/postgrey_whitelist_clients;

    • Enable SpamAssassin — mail filter for spam protection. Select this check box to enable SpamAssassin for the domain's mailboxes. Otherwise the mail domain is added into /<spamassassin directory>/local.cf;

    • ClamAV is an open source antivirus engine for checking files attached to email messages;

    • Enable DKIM for domain —  an email validation system designed to detect email spoofing by providing a mechanism to allow receiving mail exchangers to check that incoming mail from a domain is authorized by that domain's administrators. Enter the ; set the DKIM key length. The  TXT-record will be created for the mail domain of this domain after you have enabled the option. Please refer to the article Resource records. The record name is "dkim._domainkey.<Mail domain name>."; the value is "v=DKIM1; k=rsa; s=email; p=<open DKIM-key>".


      A TXT-record will be created for a domain name of the mail domain. For more information please refer to the article Resource records. The name of the record is "dkim._domainkey.<mail domain name>."; the value is "v=DKIM1; k=rsa; s=email; p=<open DKIM-key>".

      The keys are generated with the utility opendkim-genkey with the permissions of the exim user who is the owner of the mail domain:

      /bin/sh -c /usr/sbin/opendkim-genkey\ -D\ /etc/exim/ssl\ -d\ domain.com\ -s\ dkim\ -r

      The keys are kept in /<exim directory>/ssl/. The file <mail domain name>.private contains the private key, the file <mail domain name>.txt contains an open one.

  7. Select the check box Enable DMARC for the domain.  This is a mechanism helps protect incoming email from spam, spoofing, and phishing.  Enable the option to create a TXT-record for the domain name of the mail domain. Read more in Resource records. The value of this record is generated based on the template. You can edit the template in Domains → Domain names → Settings → DMARC record. Read more in Set up a DNS-server.
  8.  Select the checkbox Secure connection (SSL) if you want to use a secure connection through the SSL protocol. :
    1. Enter an Alias for certificate. The default value is "mail.<mail domain name>".
    2. Select an SSL-certificate that will be used for this mail domain. "New self-signed" is a free untrusted certificate. If you use it for a public website the connection will be considered insecure. "New Let's Encrypt certificate" is a free trusted certificate that you can use if you have set up the integration with Let's Encrypt. Learn more under Integration with Let’s Encrypt. For more information about certificates please refer to SSL certificates.
    3. Enter an Email address of the contact person.
  9. Click on Ok.


A domain name will be automatically created for the mail domain. Learn more under Create a domain name.