• How to send bulk email June 5th, 2014, by ksimpson

    Our customers often want to know how they can deliver email to enterprise recipients reliably. Usually when this question is asked, the customer has experienced some level of rejection, and has grown frustrated and confused as to why their great email is not reaching the inbox of their clients. Here’s the thing: Delivering email that […]

  • Changes to Yahoo & AOL’s DMARC Policy May 22nd, 2014, by ksimpson

    Yahoo & AOL Mail recently updated their DMARC (Domain-based Message Authentication, Reporting and Conformance) policy to “reject”. The new policy means that messages from Yahoo! and AOL addresses will be rejected by email receivers unless they originate from a Yahoo! or AOL mail server. This change makes it impossible for spammers and fraudsters to impersonate […]

  • MailChannels SMTP Relay customers protected against ‘Heartbleed’ April 10th, 2014, by ksimpson

    MailChannels takes security very seriously. MailChannels cloud services never incorporated the vulnerable software and MailChannels SMTP Relay were not affected by the security flaw discovered earlier this week. Full technical announcement here.

  • Amazon Web Services reveals i2 instance pricing – inadvertently? December 10th, 2013, by ksimpson

    Since the Amazon Re:Invent conference, many have wondered about the pricing of the new i2 instance type, which offers enormous solid state (SSD) storage options. Well, wonder no more. It seems Amazon posted a Slideshare of a talk at the Re:Invent conference, containing not only the performance details of the i3 instance type, but also […]

  • Why we should all be thankful for Nelson Mandela December 5th, 2013, by ksimpson

    Just moments ago, I heard that one of the world’s greatest men has passed – thankfully in peace with his family surrounding him. I was born in South Africa; my family left shortly thereafter, but I continue to have ties to the country through relatives, and had the fortune of visiting there a year ago. […]

  • Why do I have to set up SPF in order to use MailChannels Cloud? November 29th, 2013, by ksimpson

    Our sales people frequently get asked why clients have to update their SPF records before sending email out through MailChannels Cloud, our cloud outbound spam / email delivery solution. SPF (Sender Policy Framework), “is an email validation system designed to prevent email spam by detecting email spoofing, a common vulnerability, by verifying sender IP addresses.” […]

  • Amazon Web Services puts a cap on Spot instance pricing, takes away punchbowl November 26th, 2013, by ksimpson

    Amazon Web Services (AWS), the secretive infrastructure arm of, Inc., today announced in an email to customers that it’s going to limit the maximum bid price customers may apply to AWS Spot instances. Spot instances allow you to “name your price” on Amazon’s hosting infrastructure by putting a bid on spare capacity. If the […]

  • MX Logic blocking my mails with “554 Denied CS [*]“? October 22nd, 2013, by sridhar

    Your mails are blocked with the error message “554 Denied [CS]  [*] (Mode: normal)  (in reply to end of DATA command)” What does it mean? The mail was rejected by Mxlogic / Mcafee because of the content of the message. Steps for verification To check the IP reputation of a sending server, please to go to and […]

  • Office 365 Summarizes their Approach to Outbound Spam October 4th, 2013, by ksimpson

    Terry Zink is one of Microsoft’s best hires. He’s the anti-spam czar for Microsoft Office 365, and writes a beautiful blog post covering what Microsoft does to stop outbound anti-spam and maintain a great reputation to get their clients’ email delivered. Read more at

  • Fifty questions for Spamhaus, with our answers March 15th, 2013, by ksimpson

    Ken Magill, who writes a weekly marketing blog called “The Magill Report”, recently solicited his readers to submit questions for Steve Linford, principle at Spamhaus. Ken’s readers sent in 51 questions, and I thought it would be fun to take a crack at answering them. Here goes: 1. How can Spamhaus work directly with legitimate […]