Explanation of errors and warnings

[kubomubo]

I was backing up quite a few email addresses and during the process I got several errors and warnings. Can I get clarification which error means exactly what. Thank you very much.

W, [2023-03-24T02:46:15.915127 #1709]  WARN -- : Backup for account 'some@mail.com' failed with error Operation timed out

I, [2023-03-24T09:00:12.554128 #6931]  INFO -- : [INBOX] Fetch returned empty body - skipping

W, [2023-03-29T16:46:43.098078 #57337]  WARN -- : Backup for account 'some@mail.com' failed with error undefined method `dump' for nil:NilClass

W, [2023-04-05T16:06:44.146177 #736]  WARN -- : Backup for account 'some@mail.com' failed with error end of file reached

WARNING: More than 1000 header fields; only using the first 1000 and ignoring the rest

WARNING: Ignoring unparsable header "\xE2\x80\x9CX-AntiAbuse: This header was added to track abuse, please include it with any abuse report": invalid header name syntax: "\xE2\x80\x9CX-AntiAbuse"

[MatejKovacic]

Also for me:

WARNING: Ignoring unparsable header "po Message-ID: <xxx@xxx.si>": invalid header name syntax: "po Message-ID"
WARNING: Ignoring unparsable header "D7DE 2DE1 Content-Type: multipart/mixed; boundary=\"------------xxx\"": invalid header name syntax: "D7DE 2DE1 Content-Type"
WARNING: Ignoring unparsable header "at, 22 Oct 2022 19:03:53 +0200": invalid header name syntax: "at, 22 Oct 2022 19"
WARNING: Ignoring unparsable header "> so it cMessage-ID: <yyy@yyy.com>": invalid header name syntax: "> so it cMessage-ID"
WARNING: Ignoring unparsable header ">> zzz-Path: <zzz@zzz.si>": invalid header name syntax: ">> 6r3mueU5PmyCwTEYReturn-Path"

[joeyates]

These warnings are produced while parsing the headers of emails. The messages get backed up correctly.