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Category: Technical

DMARC=BestGuessPass

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 […]

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What is the Mail From field?

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 […]

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Office365/EOP and Outlook.com/Hotmail will converge

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 […]

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Office365/EOP IPv6 changes starting today

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 […]

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Authentication and Repudiation

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 […]

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Salesforce and DKIM

Last month I wrote about how Salesforce was implementing the ability to sign emails sent from Salesforce CRM with DKIM. The Spring 15 update is now live as is the ability to use an existing DKIM key or allow Salesforce to create a new one for you. Setting up DKIM within Salesforce is straightforward. A […]

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thirty.years.com

Thirty years ago this Sunday, symbolics.com was registered – the first .com domain. It was followed, within a few months, by bbn.com, think.com, mcc.com and dec.com. Symbolics made lisp machines – symbolics.com is now owned by a domain speculator. BBN is a technology R&D company who’ve worked on everything. If I had to pick one […]

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Salesforce SPF and now DKIM support

Salesforce has published a SPF record for sending emails from Salesforce for years and with the Spring ’15 release, they will provide the option to sign with DKIM. The SPF record is straight forward, include:_spf.salesforce.com which includes _spf.google.com, _spfblock.salesforce.com, several IP address blocks, mx, and ends with a SoftFail ~all. Salesforce Knowledge Article Number: 000006347 […]

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Mailbox preview and HTML content

I just received a slightly confusing email.     The From address and the Subject line are from Sony, but the content looks like it’s from email analytics firm Litmus. What’s going on here? Opening the mail it looks like a fairly generic “Oops, we lost a class-action lawsuit, have $2 worth of worthless internet […]

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AHBL Wildcards the Internet

AHBL (Abusive Host Blocking List) is a DNSBL (Domain Name Service Blacklist) that has been available since 2003 and is used by administrators to crowd-source spam sources, open proxies, and open relays.  By collecting the data into a single list, an email system can check this blacklist to determine if a message should be accepted […]

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