General Insights on Email Infrastructure and Deliverability

EMDAY 2019 in Paris

2 days devoted to email marketing with French experts at EMDAY 2019. One of Postmastery’s team members will be present in Paris at the EMDAY 2019 on May 16th and 17th. If you would like to have a chat with him at EMDAY,  please schedule a meeting here.

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Categories: General

Meet Postmastery at various events and summits!

CSA Summit 2019 (April 10 – 12) Postmastery sponsors CSA, and we are pleased to again attend the CSA Summit 2019 in Cologne. CSA and Postmastery share a common objective: reliable and safe email delivery. CSA enables this by providing a whitelist and related legal and compliancy services. At Postmastery, we enable this common objective […]

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Categories: General

Meet your deliverability peers at the Port25 summit, 20 September 2018, Amsterdam

This year too, Postmastery is the Premier Platinum Sponsor of the Port25 Summit. As co-organiser Postmastery’s complete team will be there to meet you. The Port25 Summit will be a highly interactive event. It brings together industry representatives, email deliverability experts, technology vendors, and senior email professionals to explore and discuss the trends that will […]

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Categories: General, PowerMTA

Delivery issues at LaPoste.net resolved

On Friday April 6, 2018, Postmastery’s Email Delivery Analytics detected serious delivery issues at LaPoste.net. The most frequent SMTP errors we detected were: 421 4.3.2 No system resources 421 4.3.2 All server ports are busy 451 4.7.1 Service unavailable – try again later 421 4.7.0 lpn-prd-vrin0xx Error: too many errors 421 4.4.2 lpn-prd-vrin0xx Error: timeout […]

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Categories: Deliverability, General, Providers

New SMTP replies at Outlook: update your backoff patterns to avoid reputation damage

On April 5th, at 5AM CET, we were alerted by a huge spike in Outlook deferrals. The chart below (copied from Postmastery Delivery Analytics) reveals the deferrals over time: After investigating the issue, Postmastery delivery engineers discovered new SMTP replies at Microsoft domains. These errors are receiver’s side, not related to sender’s reputation. Organization queue quota […]

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Categories: Authentication, Deliverability, General, Providers

AOL and Yahoo merge could impact your email delivery and MTA

A few weeks ago, AOL reported that AOL and Yahoo will come together under the OATH umbrella and merge with the Yahoo email infrastructure to serve both brands. This happened on 20 February 2018, and now all the AOL recipient domains’ MX, including the following, will point to mx-aol.mail.gm0.yahoodns.net: – aol.com – verizon.net – aol.co.uk […]

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Categories: Authentication, Deliverability, General, PowerMTA, Providers

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

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