Protecting a mail server involves a comprehensive, multi-layered approach, as hiding the IP address directly is generally not feasible. Outsourcing to a large provider is an alternative but depends on the provider's filtering capabilities. Key strategies include server hardening (strong passwords, disabling unused services, updates, and firewall configuration), implementing an IDS/IPS device, and configuring reverse proxies (like Cloudflare or Nginx, though Cloudflare is not a true SMTP proxy, while Nginx can help hide the IP). Email authentication (SPF, DKIM, DMARC) is critical to prevent spoofing, along with rate limiting, greylisting, and content filtering to mitigate attacks. Monitoring blacklists and implementing TLS encryption enhances security and deliverability. Using a dedicated IP, segmenting email lists, and throttling connections further optimize email performance and reduce abuse.
9 marketer opinions
To hide a mail server IP address and mitigate attacks, experts recommend a multi-faceted approach. This includes placing the server behind an IDS/IPS device and ensuring it's not an open relay. Implementing SPF, DKIM, and DMARC records verifies email legitimacy, while using a dedicated IP improves sender reputation. Rate limiting, greylisting, content filtering, and monitoring blacklists are essential for mitigating attacks. Restricting access with a firewall and enabling TLS encryption adds further protection. Segmenting email lists and using connection limits help prevent overload and improve engagement, reducing spam likelihood.
Marketer view
Email marketer from Gmass Blog explains segmenting email lists and sending targeted emails. This helps to improve engagement rates and reduces the likelihood of recipients marking your emails as spam.
19 Dec 2021 - Gmass Blog
Marketer view
Email marketer from Neil Patel's Blog shares that to prevent email spam and protect your server, you need to implement SPF, DKIM, and DMARC records. These authentication methods verify that your emails are legitimate and prevent spoofing.
1 Dec 2022 - Neil Patel's Blog
5 expert opinions
Hiding a mail server's IP address is generally not feasible, with outsourcing to a large provider being the primary alternative. Cloudflare is unsuitable for SMTP proxying. Mitigation strategies focus on bolstering security. Rate limiting connections is an effective way to defend against email attacks. Implementing strict transport security can increase the security of mail connections.
Expert view
Expert from Email Geeks states that there is no way to hide the IP address of a mail server, other than having someone else host it.
11 Aug 2021 - Email Geeks
Expert view
Expert from Email Geeks explains that Cloudflare is a https proxy, not an SMTP proxy. It's designed for hiding abusive websites, not mail servers.
8 Feb 2023 - Email Geeks
6 technical articles
Securing a mail server and mitigating attacks involves a combination of hardening the server, implementing protective measures, and monitoring reputation. Hardening includes strong passwords, disabling unnecessary services, keeping software updated, and configuring firewalls. Cloudflare (or Nginx) can act as a reverse proxy to protect against DDoS attacks, though Nginx also helps to hide the IP address. Rate limiting helps prevent abuse and overload. Implementing DMARC helps prevent email spoofing and phishing. Monitoring and preventing listing on the Spamhaus Block List is crucial for deliverability.
Technical article
Documentation from Cloudflare explains that Cloudflare can protect your server from DDoS attacks by acting as a reverse proxy. It filters malicious traffic and only allows legitimate requests to reach your server.
9 Jan 2025 - Cloudflare
Technical article
Documentation from Nginx explains implementing a reverse proxy configuration using Nginx to mask the actual mail server IP address and provide an additional layer of security. This involves configuring Nginx to forward requests to the mail server.
2 Oct 2023 - Nginx
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