a not really related fact. I remember reading some RFC, and the sender should tr... | Hacker News

Hacker Newsnew | past | comments | ask | show | jobs | submit

		tryauuum 30 days ago \| parent \| context \| favorite \| on: Living Dangerously with Claude a not really related fact. I remember reading some RFC, and the sender should try sending to the server specified in A record if there are no MX records present

vidarh 30 days ago | [–]

This sounds like it's an inbound check, as part of spam prevention, by seeing if the sending domain looks legitimate. There are a whole lot of those that are common that are not covered in RFCs.

rstupek 30 days ago | [–]

You are correct that is the expected order of operations

Guidelines | FAQ | Lists | API | Security | Legal | Apply to YC | Contact