Category: SMTP & Infrastructure
SMTP & InfrastructureMX records control where email for your domain gets delivered. This guide explains how MX lookups work, how to configure priority and redundancy, and what mistakes to avoid when setting up or migrating email.
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SMTP & InfrastructureSMTP error codes tell you exactly why an email didn't deliver. This guide explains what 4xx temporary errors and 5xx permanent errors mean, with the most common codes broken down by cause and how to fix them.
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SMTP & InfrastructureChoosing the wrong SMTP port can mean unencrypted connections, silent ISP blocks, or refused submissions. This guide explains ports 25, 465, 587, and 2525—what each does and when to use it.
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SMTP & InfrastructurePassword resets and order confirmations that land in spam erode user trust fast. These transactional email best practices cover infrastructure separation, authentication, From address hygiene, and monitoring.
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SMTP & InfrastructureA missing PTR record triggers Outlook to reject your mail with a 550 error. This guide explains what reverse DNS is, why mailbox providers check it, and how to configure forward-confirmed reverse DNS for your sending IP.
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