Posted in Case Studies, Deliverability, PowerMTA on 2011/11/06
A common question among professional senders is: should I use an Email Service Provider (ESP) or can I send my emails in-house? To find a good answer can be difficult. There are a lot of ESPs and a lot of software vendors ready to help you, but where to get objective advise from? My customers [...]
Posted in Case Studies on 2011/09/21
If you are a sender providing email relay services, how do you make sure that bounces and complaints are properly handled? Often the emails are generated by applications that hand-off the delivery to a relay service but have no means for processing returning bounces. This was also a question at 1-2-1 Marketing, a Texas based [...]
Posted in Deliverability on 2011/09/11
With regards to email deliverability, the inbox placement rate (IPR) is probably the most important metric. According to industry research the average IPR of permission-based commercial mail is 80%. An alarming figure, which means that 20% bounces, is dropped, or put in junk. So how can you determine how your emails are doing? One solution [...]
Posted in PowerMTA on 2011/08/31
For sending emails, there is a wealth of solutions. On the open source side, there is Sendmail, Qmail, Exim and Postfix. Then there are a number of commercial MTAs available, at different price levels. The most well known vendors are Message Systems, Port25 and StrongMail. Postfix is a popular open source MTA thanks to it’s [...]
Posted in Deliverability on 2010/07/14
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] [...]
Posted in PowerMTA on 2010/04/16
Windows Live Hotmail is famous for throttling senders based on their IP reputation. The following two SMTP errors might be familiar: 421 PR(ct1) The mail server IP connecting to Windows Live Hotmail server has exceeded the connection limit allowed. If you are not an email/network admin please contact your E-mail/Internet Service Provider for help. For [...]
Posted in Deliverability on 2010/03/30
Have you ever asked yourself who clicks on spam, and why? This month the MAAWG released a new report, the 2010 MAAWG Consumer Survey Key Findings Report, which can be downloaded here. The results from respondents give some interesting insights in consumer behavior with regards to spam and email security. The most interesting conclusions I found [...]
Posted in PowerMTA on 2010/03/17
DomainKeys, and it’s successor DKIM, are important email authentication techniques. Based on cryptography, they are more secure than SPF and Sender ID. With DomainKeys/DKIM the integrity of the content is also protected and authentication does not break when emails are being forwarded. DomainKeys/DKIM is used by large webmail providers such as Google, Yahoo and AOL. [...]
Postmastery (formerly known as Suremail) is a consulting company specialized in email infrastructure and deliverability. It is founded and led by Maarten Oelering, who focussed for ten years on email technology after having made a career in IT. Customers are email service providers, marketing agencies and other professional senders all over the world. We partner with Port25 providing licenses, integration services, and optimization services for PowerMTA.
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