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Showing posts with the label Email Server

How to Set Up an Email Forwarder & Relay Server Using Ubuntu 24.04

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We all love the rich features, familiar interface, and rock-solid reliability of personal email services like Gmail and Yahoo. However, when you are building a brand or running a small business, sending emails from a generic @gmail.com address lacks that critical professional edge. While premium suites like Google Workspace offer custom domain integration, the per-user monthly subscription fees can quickly add up—especially for startups or small operations trying to keep overhead low. Fortunately, there is a clever, cost-effective alternative: an Email Forwarder. Unlike a full-fledged mail server, an email forwarder does not store any messages on your server. It simply acts as a fast, lightweight traffic controller—catching incoming mail sent to your custom domain and instantly rerouting it to your existing personal inbox. Because it requires virtually zero local storage, you can run it on a microscopic budget. In this comprehensive guide, we will walk you through setting up a producti...

How to Prevent Email Sender Spoofing by Authenticated Users in Postfix

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Recently, one of our clients’ email addresses was compromised and used to send spam emails as part of a phishing attack. The issue occurred because one particular mailbox was configured with a weak password, allowing an attacker to gain access to the account. After successfully authenticating to the mail server, the attacker used the compromised account to send spam emails while forging a different sender identity. For example, although the legitimate account was myuser@somedomain.com , the attacker authenticated using this account but sent emails with a forged From address such as fakeuser@phishingdomain.com to distribute phishing messages. To defend against situations like this, it is important to implement multiple safeguards. In addition to educating staff to use strong but easy-to-remember passwords (so they do not write them down), administrators should configure rate limiting and enforce sender restrictions. These restrictions ensure that authenticated mailboxes can only send e...