Author Archives: Warren Duff

About Warren Duff

Warren is a Marketing Copywriter at SendGrid, specializing in email and content best practices.


Articles Posted by Warren


First Yahoo, and Now AOL. What Do You Need to Change to Be DMARC Compliant?

Posted on (0 Comments)

As you probably heard last week, Yahoo updated their DMARC policy so that mail from @yahoo.com accounts will be rejected if it isn’t sent from a Yahoo server. Now, AOL announced they are implementing the same DMARC change. AOL has changed their policy to p=reject in an effort to protect users from unauthorized use and to protect recipients from spoofing attempts. So, how can this affect you? What This Means for Senders Much like we detailed in our blog post An Update on Yahoo’s DMARC Policy, if you’re sending email with AOL.com in the From address field, messages will be

READ MORE »

An Update On Yahoo’s DMARC Policy

Posted on (0 Comments)

A recent change in Yahoo’s DMARC validation policy may be preventing your messages from being delivered. Recently, Yahoo made a significant change in their Domain-based Message Authentication, Reporting, and Conformance (DMARC) policy. DMARC is a system for implementing Domain Keys Identified Mail (DKIM) and Sender Policy Framework (SPF) validation and authentication. With a DMARC policy in place, if an email address does not match the domain server/service it originated from, it is bounced or blocked. This is a great security measure for preventing emails from companies spoofing mail domains from reaching the inbox. Yahoo has introduced a DMARC record that

READ MORE »

SMTP Service Crash Course

Posted on (0 Comments)

When you start working with email every day, you take a lot of the basics for granted. Today, we’re re-visiting what an SMTP service is with a quick Q&A with Nigel Dunetts, a member of SendGrid’s amazing Email Support team. 1. What is an SMTP service? On the most basic level, an SMTP service functions as a method to send emails from one server (or mail client) to another across the Internet. For a more in-depth guide to email and SMTP, I usually point people to the following resources: SMTP Server Relay Basics via SendGrid’s blog How Email Works via HowStuffWorks.com

READ MORE »

Trimming Unsubscribers From Your Recipient List

Posted on (0 Comments)

Maintaining your subscriber list is an essential part of any email marketing strategy because it allows you to trim away addresses in your list who don’t wish to receive your messages. Continuing to send to these messages can leave you open to being reported as spam, which can hurt your reputation and deliverability. SendGrid provides customers with two different ways to manage their marketing email subscribers: Email Reports – By enabling the Subscription Tracking App from the “Apps” section of your account, a footer will be placed at the bottom of all transactional SMTP and Web API emails. This footer

READ MORE »

SMTP Server Response Codes: What Do They Mean?

Posted on (0 Comments)

Sending email involves multiple computers communicating with each other through a process call Simple Message Transfer Protocol (SMTP). SendGrid functions as an SMTP relay service to send billions of marketing and transactional emails every month! Within the SMTP process, messages are relayed from one computer to another via SMTP servers. SMTP servers send response codes that indicate what has happened to messages. While messages are usually sent without issue, different server response codes can indicate various things. Below are a handful of SMTP server response codes that we’ve compiled that you might see when sending email: 250 – This SMTP

READ MORE »

How to Keep Your Email Looking Great in Any Inbox

Posted on (2 Comments)

Have you ever dealt with the frustration of working for hours on an email only to find out it looks completely different on one email client than it does on another? We understand how frustrating this can be, but we assure you, it’s not your fault! Every email client, like Gmail, Outlook, and Yahoo!, renders HTML and CSS differently. This means that you can create an email that looks perfect for your Gmail users, but looks different for Yahoo! users. In addition to email clients, many other things can affect how an email is displayed, including browsers, rendering engines, and

READ MORE »

IP Whitelabeling: How Does It Affect Your Email Deliverability?

Posted on (0 Comments)

If you want to improve your transactional and marketing emails, IP whitelabeling is a perfect tool. IP whitelabeling is a process that changes the domain name that appears in email headers and links. When you send an email to your customers or users through SendGrid, the email will often say “sent via SendGrid” instead of your domain name. Whitelabeling creates a few new domain name system (DNS) records that work together to display your chosen subdomain as the authenticated sender. Each record changed through the IP whitelabeling process affects something different. You’ll need to change: SPF Record – The Sender

READ MORE »