Email Relay
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TECHNOLOGY
Internet Protocols
Email Relay
Early email systems' openness became a spammer's playground, forcing a security overhaul
4 days ago
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Why did open mail relays become unpopular and widely closed on the Internet?
Because they were too expensive to maintain compared to closed relays.
Because spammers exploited them to send unsolicited emails, leading to blacklisting and security concerns.
Because they prevented users from sending emails to unknown recipients.
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