I must say it is pretty exciting with the Linux based open source solutions that are directed at solving Email Services problems: aka – SMTP + IMAP + POP3 + Spam Management (Antispam + Antivirus) + Email Administration + Web email client + DKIM + SPF.
You can assemble various solutions up together to have an effective email services.
Minimum setup for Email Services
Before you can get started you need to at least ensure your email services for a given domain has the minimum set-up completed, otherwise it is unlikely any of your email sent from your email server will actually be delivered. You would need to setup:
- SPF (Sender Policy Framework) is an email authentication standard that helps protect senders and recipients from spam, spoofing, and phishing. By adding an SPF record to your Domain Name System (DNS), you can provide a public list of senders that are approved to send email from your domain.
- DKIM or DomainKeys Identified Mail, is an email authentication method that uses a digital signature to let the receiver of an email know that the message was sent and authorised by the owner of a domain.
- Reverse IP resolves an IP to the host name of the mail server. The idea in principle is that a well behaved mail server will ensure the IP and reverse IP all match to the mail server host name and is unlikely to be sending SPAM. Likely you will need to engage with your ISP to achieve this. Failure to do this, is probably not a major issue as long as SPF and DKIM are in place.
Potential solutions for Email Services
There is plenty of Linux based solutions that can collectively work together to form a reliable Email Services.
Some recommendations would be:
- Dovecot for POP3s and IMAPs based solutions
- Haraka for SMTP and SMTPS solutions
- RSPAMD for Antispam solutions
- ClamAV for Antivirus solutions
- Sieve for filtering email messages in which it functions on the email client or mail server
- Roundcube for webmail solutions
- Redis / Database / Nginx for database and web services based solutions
Dovecot and Haraka have gained significant popularity. Dovecot, known for its efficiency and security and has become the go-to choice for businesses and individuals looking for a reliable and user-friendly email server software. Its ability to handle large mailboxes, efficient indexing, and support for multiple protocols has made it highly sought after. Haraka, on the other hand, has gained popularity for its lightning-fast performance, flexible configuration options, and powerful spam filtering capabilities for sending mail.
The combination of Dovecot and Haraka provides a robust and seamless email infrastructure, that is secure, and scalable email solution. Both software can be deployed on various operating systems, including Linux distributions such as Ubuntu, CentOS, and Debian. They are also compatible with popular cloud platforms like Amazon Web Services (AWS), Google Cloud Platform (GCP), and Microsoft Azure, enabling easy scalability and deployment in virtualised environments. Additionally, Dovecot and Haraka can run on physical servers or be containerised using technologies like Docker or Kubernetes, facilitating efficient resource utilisation.