To expand on this, site admins can see the transaction information from the receiving mail server for every single email that gets sent out.
For example:
This queue ID (289B51004DF) is the proof of delivery to the mail server… and in turn that mail server will [should] get a queue ID when the next server accepts the mail.
For sites hosted on our platform, we can easily search this queue ID (site admins need to contact us to do the lookup) to get that information. For example, here’s the results from the above email:
2023-09-14T09:02:16.000Z,289B51004DF,
"to=<«redacted».anonaddy.me>,
relay=mail2.anonaddy.me[2a04:3544:8000:1000:e8b5:6ff:fe29:56c]:25,
delay=10,
delays=0.29/0/8.3/1.6,
dsn=2.0.0,
status=sent (250 2.0.0 Ok: queued as ED640FAC90)"
So if you complained (for instance) about not getting this email from us, you could now go to anonaddy and say “mail2.anonaddy.me
accepted an email for me at 2023-09-14T09:02:16Z with queue ID ED640FAC90
, can you trace what happened to it?” and they will be able to check their logs.
Site admins not on our platform would need to do essentially the same process.