Ten identical (?) emails - why / how?

[JStone]

OK, it's an important event. But why / how did I receive 10 apparently identical COVID-19 vaccination reminders from NHS Booking this morning? Same content & date / time sent. Gmail account viewed in Apple Mail on iMac. BTW, I'm happy to receive a reminder, just curious about the repeats.

Digging into the headers, there are a few differences in obscure (to me) strings.

eg one has:
X-Received: ⁨by 2002:a17:906:cf82:: with SMTP id um2mr2809900ejb.322.1619768421160; Fri, 30 Apr 2021 00:40:21 -0700 (PDT)⁩
Return-Path: ⁨<0102017921b8a8fe-08492fb0-1dc8-4910-9852-48c1cb28e633-000000@mail.notifications.service.gov.uk>⁩
...
Received: ⁨from e239-68.smtp-out.eu-west-1.amazonses.com (e239-68.smtp-out.eu-west-1.amazonses.com. [23.251.239.68]) by mx.google.com with ESMTPS id h4si1069611ede.481.2021.04.30.00.40.20 for <my email address> (version=TLS1_2 cipher=ECDHE-ECDSA-AES128-SHA bits=128/128); Fri, 30 Apr 2021 00:40:21 -0700 (PDT)⁩

while another has:
X-Received: ⁨by 2002:a17:906:4098:: with SMTP id u24mr2752964ejj.228.1619768421160; Fri, 30 Apr 2021 00:40:21 -0700 (PDT)⁩
Return-Path: ⁨<0102017921b8a8ff-26260a58-6993-45dd-9c0d-bedabc9f553c-000000@mail.notifications.service.gov.uk>⁩
...
Received: ⁨from e239-82.smtp-out.eu-west-1.amazonses.com (e239-82.smtp-out.eu-west-1.amazonses.com. [23.251.239.82]) by mx.google.com with ESMTPS id b6si2941661ejb.254.2021.04.30.00.40.20 for <my email address> (version=TLS1_2 cipher=ECDHE-ECDSA-AES128-SHA bits=128/128); Fri, 30 Apr 2021 00:40:21 -0700 (PDT)⁩

-------
Is there some kind of internal bouncing going on somewhere? What would cause 10 copies of the same message?

[DaveReading]

Which politician's mate had the contract for writing the application ?

[Mr Larrington]

Probably Dido, Queen of Carnage.

[Polar Bear]

Which politician's mate had the contract for writing the application ?

I doubt that the contract is that specific.  One could be held to a count if one has to actually deliver something.

[Jaded]

Have a close look at the source and see if you can find the phrase "farrago of nonsense" in there.

[drossall]

Is there some kind of internal bouncing going on somewhere? What would cause 10 copies of the same message?

Because mail is passed from server to server, an acknowledgement has to go back on receipt at each hop. I've come across cases where the message is passed successfully, but the acknowledgement isn't, so the sender sends the message again. That results in duplicates. If you follow the headers through, you can sometimes see where those for the two messages diverge - which was the point where the duplicates were generated.

[Kim]

Is there some kind of internal bouncing going on somewhere? What would cause 10 copies of the same message?

Because mail is passed from server to server, an acknowledgement has to go back on receipt at each hop. I've come across cases where the message is passed successfully, but the acknowledgement isn't, so the sender sends the message again. That results in duplicates. If you follow the headers through, you can sometimes see where those for the two messages diverge - which was the point where the duplicates were generated.

Particularly common when multiple messages are transferred in one connection, such as when delivering to a mailing list or flushing a queue after a connectivity outage, but the process is interrupted by notwork problems before it's completed.

The thing about network outages is they're extremely likely to happen when the network's just come back up from an outage...

[JStone]

Have a close look at the source and see if you can find the phrase "farrago of nonsense" in there.

No nonsensical farragos detected. Or Farages.

A friend suggested that ten appointment emails might be some devious plot to inflate the vaccination progress figures - though the no-show stats will be pretty bad if only one of me turns up. Still, it's nice to feel wanted.

[Jaded]

They might think you are a bit forgetful?