Email Delivery Errors and SMTP Codes: What They Mean and How to Fix Them
You hit send. The recipient never gets it. Back comes a wall of text with something like 550 5.7.26 buried in it, and now you have to figure out which part to actually read.
Email Delivery & Tips
Practical advice on improving email deliverability, avoiding spam filters, and getting more messages into the inbox. We share tips, explanations, and best practices drawn from real-world sending.
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Reaching Donors’ Inboxes: A 2026 Guide to Nonprofit Email Deliverability
A guide for nonprofits to improve email deliverability, reach donors’ inboxes, and boost engagement and fundraising results.
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Out of Office Message Examples: 22 Copy-Paste Templates for Every Scenario
You came here for templates. They’re below. But first, the safest default for most people:
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Hard Bounce vs Soft Bounce: What They Mean and How to Fix Them
You sent the email. The recipient never got it. Now your dashboard says “hard bounce” or “soft bounce” or, if you’re an SMTP2GO user, possibly “rejected.” Three different statuses, three different causes, three different things you should do about them.
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Email Headers: What They Are and Why We Ask For Them
What are email headers? Are they dangerous to share? And why do we ask to see them instead of just reading the email itself?
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SMTP2GO Sending Limits: The Complete Reference
We believe in being limitless wherever we can. But every email service worth trusting has a few guardrails in place, and ours exist for a single reason: to protect the deliverability of every sender on our network.
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