Email Authentication: SPF, DKIM, and DMARC Best Practices
Improve Email Delivery with PowerMTA’s Defer-Job Setting
2023/04/14 by Alex Irimia.
Email delivery is a critical aspect of any business’s communication strategy. However, maintaining a good reputation for your email delivery IP can be a challenge, especially when using a shared IP with multiple customers. In such a scenario, the actions of one customer with a low reputation can adversely affect the entire queue, causing delays […]
Categories: Authentication, Deliverability, General, PowerMTA
Postmastery joins Signal Spam
2023/02/20 by Willem Stam.
Postmastery is becoming a member of Signal Spam to ensure our clients have maximum visibility into reputational threats and complaints emanating from the french eco-system. Signal Spam is a non-profit organisation dedicated to fighting against electronic messaging abuse, including spam, phishing, and malicious email content. It was founded in 2005 and is based in Paris, […]
Categories: Authentication, Deliverability, General
New SMTP replies at Outlook: update your backoff patterns to avoid reputation damage
2018/04/06 by Willem Stam.
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 […]
Categories: Authentication, Deliverability, General, Providers
AOL and Yahoo merge could impact your email delivery and MTA
2018/02/26 by Willem Stam.
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 […]
Categories: Authentication, Deliverability, General, PowerMTA, Providers
Case study – Why typo domains can cause severe email delivery issues
2018/02/26 by Willem Stam.
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 […]
Categories: Authentication, Case Studies, Deliverability, General, PowerMTA
Happy client: SuccessByEmail.com
2017/11/24 by Willem Stam.
“I would like to thank the PowerMTA email delivery experts at Postmastery. Postmastery was incredibly responsive to our specific delivery needs and wasted no time in taking a scientific approach to identify specific issues and formulate a path to resolution. From precise data collection and analysis to resolution recommendations and follow up, Postmastery does a […]
Categories: Authentication, Case Studies, General
Choosing the right DMARC policy
2017/07/13 by Willem Stam.
Publishing DMARC records is more popular than ever. Even among those that don’t have domains related to sensitive fields, such as financial institutions, that are vulnerable to abuse. Have you thought about the policy that underpins your objectives for DMARC? Do you even have clear objectives for DMARC? DMARC policies DMARC requires three policies: none, […]
Categories: Authentication, DMARC, General