SendGrid's Email Deliverability Blog

From email deliverability best practices, to hackathon highlights, API tutorials, and everything in between, the SendGrid blog is your destination for all things email. Browse our most recent posts in the main feed or filter by category. Be sure to subscribe to the blog to get a daily digest of posts and reach out to us in the comments to let us know how we're doing.


How SendGrid Found the SpamAssassin Y2K10 Rule Bug

Product, Technical
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One of the many things SendGrid does on the backend to determine if a user is having deliverability problems is scan the content through multiple enterprise spam filters multiple times per day for every user.  Some of the filters include Postini, CloudMark, Brightmail, IronPort, Barracuda, Mail Foundry, and SpamAssassin.  These filters are additional filters from our delivery monitory to ISPs such as Hotmail, Yahoo, Gmail, and AOL.  In the last couple of days we noticed that a lot of legitimate emails were triggering the SpamAssassin filter.  The following shows how our graph looks like: … Read more ›


A Look at the World of Sending Political Emails

Jacob Hansen Best Practices
Illustration of a blue ballot box with an envelope

With the election season well under way, you may have noticed an influx of emails getting to your inbox from various political organizations. As one of the Delivery Consultants at SendGrid, I wanted to look into political sending, what’s unique about it, how it relates to other types of marketing email, and provide some tips on improving political email performance. How do … Read more ›