On Monday I talked about how big IPv6 address space is, and how many IPv6 addresses will be available to end users. We’re mostly an email blog, though, so what’s the relevance to sending email? If the recipient you’re sending to has an IPv6 mailserver you can send mail to them over IPv6, if you choose to. If they only have an IPv6 mailserver, with no IPv4 mailserver at all then...
IPv6 is big. Really big. You just won’t believe how vastly, hugely, mind-bogglingly big it is. I mean, you may think it’s a long way down the road to the chemist, but that’s just peanuts to IPv6. The old Internet, the one you’re probably using right now, runs on IP version 4. IPv4 addresses have numbers and dots; they look like 172.224.4.56. There are about 4,009,754,624...
Microsoft Send is a new mail client by Microsoft for iPhones and soon Windows Phone and Android phones. Send is designed to send quick, short messages to contacts. Instead of building a chat application build on a proprietary protocol, Send sends and receives its messages over email and uses your existing mailbox to handle the messages. What makes Send neat is that I can start a conversation...
I received this email earlier this week, an email that I wanted but this is how it arrived. The email contained a single image link, a text line of who the message was sent to, the senders name, address, and finally an unsubscribe link. Good news, the email is CAN-SPAM compliant! Bad news, I have no idea what the content of the message is and it looks somewhat spammy. The email was sent to my...
PTR records are easy to over look and they have a significant impact on your ability to deliver mail without them. Some ISP and mailbox providers will reject mail from IP addresses that do not have a PTR record created. PTR records are a type of DNS record that resolves an IP address to a fully qualified domain name or FQDN. The PTR records are also called Reverse DNS records. If you are...
Looking at the headers within the mail received with my Office365 domain I see dmarc=bestguesspass. BestGuessPass? That’s a new. A few days after seeing dmarc=bestguesspass, Terry Zink at Microsoft posted an explanation. Exchange Online Protection, the filtering system for Office365, is analyzing the authentication of incoming emails and if the domain is not publishing a DMARC record, EOP...
When emails are sent, there are two from fields, the Mail From and the Display From address. The Display From address (technically referred to as RFC.5322 from address) is the from address that is displayed to the end user within their email client. The Mail From (technically referred to as RFC.5321 from address) is the email address to which bounce messages are delivered. The Mail From field...
Terry Zink posted two informative blog posts recently, the first being the change to unauthenticated mail sent over IPv6 to EOP and the second post about EOP (Office365 and Exchange Hosting) and Outlook.com/Hotmail infrastructure converging. Exchange Online Protection (EOP) is the filtering system in place for Office 365 and hosted Exchange customers. Outlook.com/Hotmail utilized its own mail...
Terry Zink at Microsoft posted earlier this week that Office365/Exchange Online Protection will have a significant change this week. Office365 uses Exchange Online Protection (EOP) for spam filtering and email protection. One of the requirements to send to EOP over IPv6 is to have the email authenticated with either SPF or DKIM. If the mail sent to Office365/EOP over IPv6 is not authenticated...
Email Authentication lets you demonstrate that you sent a particular email. Email Repudiation is a claim that you didn’t send a particular email. SPF is only for email authentication1 DKIM is only for email authentication DMARC is only for email repudiation 1 SPF was originally intended to provide repudiation, but it didn’t work reliably enough to be useful. Nobody uses...
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