In essence, the question is this: there's a server hosting multiple sites with different domains, but the IP address is the same for all.
The goal is to ensure that each site has its own mail with unique POP3 and SMTP settings (e.g. example.com, pop3.example.com, smtp.example.com), and this applies to every site.
How can this be achieved?
DNS Setup and Configuring the server part.
For DNS Setup, an A-record needs to be registered for each web and mail host, indicating its IP. Similarly, an MX record needs to be set up to indicate the mail server for the domain with priorities.
As for Configuring the server part, virtual servers need to be created for Apache in the config, and support domains and mailbox aliases need to be registered for the mailer (sendmail).
Ultimately, when websites or emails are accessed, the corresponding server will identify the requested domain and mailbox and work accordingly.
To avoid issues with mail delivery due to spam filters, it's recommended to park all domains on domain.google.com and set up A records to make the sites function properly.
Setting up a comprehensive mail system on your own server can be a cumbersome task.
Many factors are affected by the operating system and software utilized. A case in point is when utilizing Apache web server, you can establish virtual hosts by name on a single IP address. In the instance of email services, there are products like vpopmail that can be used.
Typically, authentication is performed based on the entire email address instead of just the login information which ensures that the system identifies the connected domain. Multiple imap/pop3 services can function together with vpopmail.
One such popular service is dovecot.
To achieve this, you can set up a mail server that supports virtual hosting. This allows you to configure separate mail settings for each domain hosted on the server, even though they share the same IP address.
Here's a general outline of how you can approach this:
1. Install and configure a mail server software such as Postfix or Exim on the server.
2. Configure the mail server to support virtual hosting. This typically involves creating separate configuration files or sections for each domain.
3. For each domain, create a DNS entry that points the mail-related subdomains (e.g., pop3.example.com, smtp.example.com) to the server's IP address.
4. Set up the necessary authentication and encryption mechanisms (e.g., SSL/TLS) to secure the mail connections.
5. Configure the mail server to handle incoming and outgoing mail for each domain separately, with unique POP3 and SMTP settings. This can include specifying different mail directories, authentication databases, and access controls for each domain.
6. Test the configuration by sending and receiving emails for each domain to ensure that everything is working as expected.
additional details and considerations for achieving separate mail settings for each domain hosted on a server:
1. Mail Server Software: Choose a mail server software that supports virtual hosting and is compatible with your operating system. Some popular options include Postfix, Exim, and Dovecot.
2. DNS Configuration: In addition to setting up the subdomains (e.g., pop3.example.com, smtp.example.com) to point to the server's IP address, configure DNS MX records for each domain to ensure incoming mail is directed to the correct mail server.
3. Authentication: Decide on the authentication method you want to use for each domain's email accounts. Common options include local system accounts, LDAP authentication, or database-driven authentication.
4. SSL/TLS: Implement SSL/TLS certificates for secure communications between the mail client and server. This is important for protecting sensitive information like login credentials.
5. Mailbox Storage: Determine how you want to store the emails for each domain. You can choose to store them in separate directories, databases, or even cloud storage solutions.
6. Spam and Virus Filtering: Configure spam and virus filters specific to each domain to ensure proper identification and handling of unwanted or malicious emails.
7. Monitoring and Maintenance: Regularly monitor your mail server for any issues, such as system resource usage, email queue length, and security vulnerabilities. Stay up to date with software updates and patches to ensure a secure and stable environment.