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Top 6 SendGrid alternatives

If you’re looking for a new ESP, this post breaks down six top-tier SendGrid alternatives. We’re looking at things like reliable email APIs, transactional messaging features, and varying levels of deliverability tools. Whether you need...

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5 best email service platforms with free plans

We’ve evaluated five of the most reliable email service platforms offering free tiers. Each provider has a different take on what “free” means, so we’ve broken it down for clarity.

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10 ways to improve and protect your sender reputation

What’s sender reputation? Glad you asked. In this article, we define what sender reputation is and its components, we’ll cover our top tips, and some of the most common mistakes...

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“Email failed to send” – understanding the error message?

Let’s say you’ve integrated your app with email functionality, designed some great email content, developed a marketing strategy, and you think you’re good to go. But then you...

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DKIM pass, bounce anyway? Outlook's new mystery rejection

Over the past few weeks, a rising number of Mailgun customers (and industry peers across other ESPs) have encountered bounce messages. In short:

DKIM appears to pass in one place (like Gmail or your DMARC reports) but fails at Microsoft.

And when it fails, Outlook blocks the message, even if it meets standard DMARC policy of p=none...

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Deliverability academy episode 2 recap: New rules, same inbox

If you're still treating deliverability like an afterthought, your emails probably aren't landing where you want them to. In the second episode of Mailgun’s Deliverability Academy, hosts Natalie Hayes and Alison Gootee bring their expertise...

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Email authentication: Your ID card for sending

Email authentication lets mailbox providers know that you’re a trusted sender – that you are who you say you are. As a Technical Account Manager at Mailgun, I’m constantly...

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B2B vs. B2C email engagement and deliverability challenges: What really works in 2025

B2B and B2C recipients don’t just behave differently – they prioritize different outcomes, respond to different signals, and operate in entirely different decision cycles. And with new deliverability requirements...

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