Smaller mail systems are able to verify the email address during the RFC 821 "MAIL TO:" command and reject it before the body of message is sent. The onus is then on the sending MTA to advise sender of non delivery. If receiving MTA receives message and then checks validity of destination, the onus is on it to issue non delivery.
"view source" of message if Google allows should reveal IP of original sender, and IP who sent the non-delivery notification.
Jean-Francois Mezei
npub1v3…c3sjg
2025-04-15 22:36:26 UTC
in reply to nevent1q…3d4l
Author Public Key
npub1v3ecul8au8n5m0gnve0uq794se7gk4fw65uheh46e2r05y2csmgq8c3sjgSeen on
wss://relay.momostr.pinkPublished at
2025-04-15 22:36:26 UTCEvent JSON
{
"id": "3d1d6c6488c9bcc91b939fccd7af2350428d5dccb10705d80debdbcdc90145ff",
"pubkey": "64738e7cfde1e74dbd13665fc078b5867c8b552ed5397cdebaca86fa115886d0",
"created_at": 1744756586,
"kind": 1,
"tags": [
[
"e",
"f28ab5d10d64170e9fe4e644c7675dbdd9905fe8dcfb9315bd291a34a59815b7",
"",
"root",
"fe31a74ce7a735689686a4a8bdb765a8f4db945d91b67412c75058a82a51cffd"
],
[
"p",
"fe31a74ce7a735689686a4a8bdb765a8f4db945d91b67412c75058a82a51cffd"
],
[
"proxy",
"https://mstdn.ca/@jfmezei/114344367670095917",
"web"
],
[
"proxy",
"https://mstdn.ca/users/jfmezei/statuses/114344367670095917",
"activitypub"
],
[
"L",
"pink.momostr"
],
[
"l",
"pink.momostr.activitypub:https://mstdn.ca/users/jfmezei/statuses/114344367670095917",
"pink.momostr"
],
[
"-"
]
],
"content": "Smaller mail systems are able to verify the email address during the RFC 821 \"MAIL TO:\" command and reject it before the body of message is sent. The onus is then on the sending MTA to advise sender of non delivery. If receiving MTA receives message and then checks validity of destination, the onus is on it to issue non delivery. \n\n\"view source\" of message if Google allows should reveal IP of original sender, and IP who sent the non-delivery notification.",
"sig": "076bcf69facf00b1c9e73382d1a91b47ced0d494017396ad0894c2e6182790a0bd043d245f6ab0c7930aefccf1e769138b45793a49694e26f827766f83288a77"
}