Case study – Why typo domains can cause severe email delivery issues

In our daily email delivery monitoring activities, we recently saw the damage that typo domains can do. In this case study, simple typos in domains caused severe email delivery issues. We will recap what happened and how we solved the issue. Hopefully, other senders can avoid this kind of situation in the future. Postmastery, we […]

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Categories: Authentication, Case Studies, Deliverability, General, PowerMTA

Email domain best practices

Domains in emails are important for identification, trust and reputation. But emails can embed many domains used for different purposes. They are listed below: IP hostname Envelope sender domain From header domain Reply-To header domain Sender header domain Message-ID domain DKIM signing domain Image URI domain(s) Link URI domain(s) This post provides some background on […]

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Categories: Authentication, Deliverability, General

On the classification of bounces

Delivering large volumes of email can be difficult. Properly handing the bounces can be even more challenging. To decode, analyze and classify the hundredths of different bounce mail formats is a complex task. To give you an idea what you might encounter, here are some examples of bounces: 421 4.7.1 Intrusion prevention active for [X.X.X.X] […]

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Categories: Authentication, Deliverability, General