The Deliverable Diary

We’ve made several new enhancements to our email API features, designed to give you more control, better performance and greater flexibility when sending emails at scale. From scheduling emails in advance to dramatically improving throughput and sending large batches more efficiently, these updates make it easier than ever to integrate powerful email workflows into your […]

Short answer: Yes, Gmail is still blocked in mainland China in 2026, the same as it’s been since 2014. If you need to read your inbox, you’ll want a VPN, an international eSIM, or roaming. But if your real problem is sending (an app, a website, a CRM, a printer, or just Outlook trying to […]

The rules quietly changed in February 2024. If your unsubscribe guide is older than that, it’s giving you 2014 advice for 2026 inboxes. Here’s what happened. Gmail and Yahoo started enforcing new requirements for any sender pushing more than 5,000 messages a day to their inboxes. One of those requirements: a working one-click unsubscribe, implemented […]

Most email attachment size guides give you a number and call it done. The problem is that the number on the box isn’t the number that actually sends. Encoding adds weight, recipient servers have their own caps, and a 24 MB file can bounce off a 25 MB limit without ever reaching an inbox. This […]

Transactional SMS is the text your customer gets the second something happens on their account. The shipping label is printed. The login attempt fires. The appointment is 30 minutes out. It’s automated, it’s triggered by an event, and it carries information the recipient actually wants. Marketing? That’s a separate animal with separate rules. This guide […]

SMTP relay is the service that takes an outgoing email from your app, website, or device and hands it off to the recipient’s mail server on your behalf. If you send more than a handful of emails a day, especially the automated ones (password resets, order receipts, alerts, newsletters), you’re almost certainly relying on a […]