· 5 min
Most of our contacts sat idle while the bill tracked the list. We rebuilt on the raw sending layer. What that actually cost, the work nobody puts on a pricing page, what broke, and when you should not do this.
· 4 min
Resend answers 429 for a rate limit, a spent daily quota and a spent monthly quota. A retry loop that looks at the status treats all three the same, and two of them do not clear for hours or weeks. How to tell them apart, and how we split the same three cases.
· 6 min
When an agent gets an error, it has to pick one of three things to do next: retry, fix the request, or stop and tell a person. Why a spent plan is a 402, why two 429s mean opposite things, and the day we collapsed a dozen error names into one vocabulary.
· 5 min
Corporate security gateways open every link in a message within a second of delivery, with a browser's user agent, and a click tracker records each one as a reader. Of 1,766 clicked messages, 884 were scanned rather than read. The signature that gives them away, why you cannot judge it from the first hit, and what an agent acting on a click should see.
· 4 min
Two customers reply to "Re: Invoice" on the same afternoon. Subject matching puts them in one thread, and an agent reading it leaks one customer's context into a reply to the other. How SendRaven joins replies instead.
