output 1324764631.3974 = SEEN

Running ubuntu-21.04
Running fetchmail -V:
,----
| This is fetchmail release 6.4.16+GSS+NTLM+SDPS+SSL-SSLv2-SSLv3+NLS+KRB5.
| Compiled with SSL library 0x101010af "OpenSSL 1.1.1j  16 Feb 2021"
| Run-time uses SSL library 0x101010af "OpenSSL 1.1.1j  16 Feb 2021"
| OpenSSL: OPENSSLDIR: "/usr/lib/ssl"
| Engines: ENGINESDIR: "/usr/lib/x86_64-linux-gnu/engines-1.1"
`----


If I run `fetchmail -vvvc', the tail of output shows:

        1324764631.3974 = SEEN
        1324764631.3975 = SEEN
          [...] snipped 17 more similar line

        1324764631.4032 = SEEN

Even if I've just run `fetchmail -vvva'  making sure fetchmail knows
to retrieve all seen or not.

At a glance it seems to be reporting mail on the server that has been
viewed.

But, even in ~/.fetchmailrc I've told fetchmail `fetchall'

Maybe those `SEEN' lines mean something else?

my server is fastmail.com

~/.fetchmailrc (email addr and passwd munged):
  # set timeout 40
  # set daemon 600
  # set logfile /home/reader/t/var/log/fetchmail.log

  poll pop.fastmail.com  proto POP3 user MUNGED  password MUNGED.

  ssl
  ## sslproto ''
  fetchall
  no keep
  no rewrite
  
  mda "/usr/bin/procmail -f %F -d %T";

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