I’ve configured an incoming mail account for my iCloud mail account over IMAPS.

The connection works without problems but when the emails are fetched the error Could not fetch message ‚1‘, answer from server was empty. occurs every time.

Full communication protocol:
1 |   | Kernel::System::MailAccount::IMAP | Open connection to ‚imap.mail.me.com‘ (*redacted*@icloud.com). | 15.02.2024 15:57:37 (Europe/Berlin)
— | — | — | — | —
2 |   | Kernel::System::MailAccount::IMAP | 1 messages available for fetching (*redacted*@icloud.com/imap.mail.me.com). | 15.02.2024 15:57:38 (Europe/Berlin)
3 |   | Kernel::System::MailAccount::IMAP | Prepare fetching of message ‚1/1‘ (Size: 14.3 KB) from server. | 15.02.2024 15:57:39 (Europe/Berlin)
4 |   | Kernel::System::MailAccount::IMAP | Could not fetch message ‚1‘, answer from server was empty. | 15.02.2024 15:57:39 (Europe/Berlin)
5 |   | Kernel::System::MailAccount::IMAP | Fetched 1 message(s) from server (*redacted*@icloud.com/imap.mail.me.com). | 15.02.2024 15:57:39 (Europe/Berlin)
6 |   | Kernel::System::MailAccount::IMAP | Executed deletion of marked messages from server (*redacted*@icloud.com/imap.mail.me.com). | 15.02.2024 15:57:39 (Europe/Berlin)
7 |   | Kernel::System::MailAccount::IMAP | Connection to ‚imap.mail.me.com‘ closed. | 15.02.2024 15:57:40 (Europe/Berlin)

Output of docker exec -t -u otobo otobo-web-1 bin/otobo.Console.pl Maint::PostMaster::MailAccountFetch –debug
Spawning child process to fetch incoming messages from mail accounts…

imap.mail.me.com (IMAPS)…
[…cpan-lib/Net/IMAP/Simple.pm line 133 in sub _connect] connecting to imap.mail.me.com:993
[…cpan-lib/Net/IMAP/Simple.pm line 133 in sub _connect] connected, returning socket
[…System/MailAccount/IMAPS.pm line 52 in sub new] waiting for socket ready
[…System/MailAccount/IMAPS.pm line 52 in sub new] looking for greeting
[…System/MailAccount/IMAPS.pm line 52 in sub new] got a greeting: * OK [CAPABILITY XAPPLEPUSHSERVICE IMAP4 IMAP4rev1 SASL-IR AUTH=ATOKEN AUTH=PLAIN] (2409B28-0aafd8d46d30) ms11p00im-qufv17101501.me.com\r\n
[…cpan-lib/Net/IMAP/Simple.pm line 1251 in sub _send_cmd] 0 LOGIN *redacted*@icloud.com „redacted-password“\r\n
[…cpan-lib/Net/IMAP/Simple.pm line 265 in sub _process_cmd] 0 OK user *redacted* logged in\r\n
[…cpan-lib/Net/IMAP/Simple.pm line 1276 in sub _cmd_ok] 0 OK user *redacted* logged in\r\n
[…cpan-lib/Net/IMAP/Simple.pm line 1251 in sub _send_cmd] 1 SELECT „Info“\r\n
[…cpan-lib/Net/IMAP/Simple.pm line 413 in sub _process_cmd] * 1 EXISTS\r\n
[…cpan-lib/Net/IMAP/Simple.pm line 1276 in sub _cmd_ok] * 1 EXISTS\r\n
[…cpan-lib/Net/IMAP/Simple.pm line 413 in sub _process_cmd] * 0 RECENT\r\n
[…cpan-lib/Net/IMAP/Simple.pm line 1276 in sub _cmd_ok] * 0 RECENT\r\n
[…cpan-lib/Net/IMAP/Simple.pm line 413 in sub _process_cmd] * OK [UNSEEN 1]\r\n
[…cpan-lib/Net/IMAP/Simple.pm line 1276 in sub _cmd_ok] * OK [UNSEEN 1]\r\n
[…cpan-lib/Net/IMAP/Simple.pm line 413 in sub _process_cmd] * OK [UIDVALIDITY 1667977415]\r\n
[…cpan-lib/Net/IMAP/Simple.pm line 1276 in sub _cmd_ok] * OK [UIDVALIDITY 1667977415]\r\n
[…cpan-lib/Net/IMAP/Simple.pm line 413 in sub _process_cmd] * OK [UIDNEXT 2]\r\n
[…cpan-lib/Net/IMAP/Simple.pm line 1276 in sub _cmd_ok] * OK [UIDNEXT 2]\r\n
[…cpan-lib/Net/IMAP/Simple.pm line 413 in sub _process_cmd] * FLAGS (\Answered \Flagged \Draft \Deleted \Seen \Recent $MailFlagBit0 $MailFlagBit1 $MailFlagBit2 $Forwarded Redirected $NotJunk NotJunk)\r\n
[…cpan-lib/Net/IMAP/Simple.pm line 1276 in sub _cmd_ok] * FLAGS (\Answered \Flagged \Draft \Deleted \Seen \Recent $MailFlagBit0 $MailFlagBit1 $MailFlagBit2 $Forwarded Redirected $NotJunk NotJunk)\r\n
[…cpan-lib/Net/IMAP/Simple.pm line 413 in sub _process_cmd] * OK [PERMANENTFLAGS (\Answered \Flagged \Draft \Deleted \Seen \Recent $MailFlagBit0 $MailFlagBit1 $MailFlagBit2 $Forwarded Redirected $NotJunk NotJunk \*)]\r\n
[…cpan-lib/Net/IMAP/Simple.pm line 1276 in sub _cmd_ok] * OK [PERMANENTFLAGS (\Answered \Flagged \Draft \Deleted \Seen \Recent $MailFlagBit0 $MailFlagBit1 $MailFlagBit2 $Forwarded Redirected $NotJunk NotJunk \*)]\r\n
[…cpan-lib/Net/IMAP/Simple.pm line 413 in sub _process_cmd] 1 OK [READ-WRITE] SELECT completed (took 9 ms)\r\n
[…cpan-lib/Net/IMAP/Simple.pm line 1276 in sub _cmd_ok] 1 OK [READ-WRITE] SELECT completed (took 9 ms)\r\n
IMAPS: Message 1/1 (*redacted*@icloud.com/imap.mail.me.com)
[…cpan-lib/Net/IMAP/Simple.pm line 1251 in sub _send_cmd] 2 FETCH 1 RFC822.SIZE\r\n
[…cpan-lib/Net/IMAP/Simple.pm line 586 in sub _process_cmd] * 1 FETCH (RFC822.SIZE 14640)\r\n
[…cpan-lib/Net/IMAP/Simple.pm line 1276 in sub _cmd_ok] * 1 FETCH (RFC822.SIZE 14640)\r\n
[…cpan-lib/Net/IMAP/Simple.pm line 586 in sub _process_cmd] 2 OK FETCH completed (took 50 ms)\r\n
[…cpan-lib/Net/IMAP/Simple.pm line 1276 in sub _cmd_ok] 2 OK FETCH completed (took 50 ms)\r\n
[…cpan-lib/Net/IMAP/Simple.pm line 1251 in sub _send_cmd] 3 FETCH 1 RFC822\r\n
[…cpan-lib/Net/IMAP/Simple.pm line 736 in sub _process_cmd] * 1 FETCH ()\r\n
[…cpan-lib/Net/IMAP/Simple.pm line 1276 in sub _cmd_ok] * 1 FETCH ()\r\n
[…cpan-lib/Net/IMAP/Simple.pm line 736 in sub _process_cmd] 3 OK FETCH completed (took 58 ms)\r\n
[…cpan-lib/Net/IMAP/Simple.pm line 1276 in sub _cmd_ok] 3 OK FETCH completed (took 58 ms)\r\n

[…cpan-lib/Net/IMAP/Simple.pm line 1251 in sub _send_cmd] 4 SELECT „Info“\r\n
[…cpan-lib/Net/IMAP/Simple.pm line 413 in sub _process_cmd] * 1 EXISTS\r\n
[…cpan-lib/Net/IMAP/Simple.pm line 1276 in sub _cmd_ok] * 1 EXISTS\r\n
[…cpan-lib/Net/IMAP/Simple.pm line 413 in sub _process_cmd] * 0 RECENT\r\n
[…cpan-lib/Net/IMAP/Simple.pm line 1276 in sub _cmd_ok] * 0 RECENT\r\n
[…cpan-lib/Net/IMAP/Simple.pm line 413 in sub _process_cmd] * OK [UNSEEN 1]\r\n
[…cpan-lib/Net/IMAP/Simple.pm line 1276 in sub _cmd_ok] * OK [UNSEEN 1]\r\n
[…cpan-lib/Net/IMAP/Simple.pm line 413 in sub _process_cmd] * OK [UIDVALIDITY 1667977415]\r\n
[…cpan-lib/Net/IMAP/Simple.pm line 1276 in sub _cmd_ok] * OK [UIDVALIDITY 1667977415]\r\n
[…cpan-lib/Net/IMAP/Simple.pm line 413 in sub _process_cmd] * OK [UIDNEXT 2]\r\n
[…cpan-lib/Net/IMAP/Simple.pm line 1276 in sub _cmd_ok] * OK [UIDNEXT 2]\r\n
[…cpan-lib/Net/IMAP/Simple.pm line 413 in sub _process_cmd] * FLAGS (\Answered \Flagged \Draft \Deleted \Seen \Recent $MailFlagBit0 $MailFlagBit1 $MailFlagBit2 $Forwarded Redirected $NotJunk NotJunk)\r\n
[…cpan-lib/Net/IMAP/Simple.pm line 1276 in sub _cmd_ok] * FLAGS (\Answered \Flagged \Draft \Deleted \Seen \Recent $MailFlagBit0 $MailFlagBit1 $MailFlagBit2 $Forwarded Redirected $NotJunk NotJunk)\r\n
[…cpan-lib/Net/IMAP/Simple.pm line 413 in sub _process_cmd] * OK [PERMANENTFLAGS (\Answered \Flagged \Draft \Deleted \Seen \Recent $MailFlagBit0 $MailFlagBit1 $MailFlagBit2 $Forwarded Redirected $NotJunk NotJunk \*)]\r\n
[…cpan-lib/Net/IMAP/Simple.pm line 1276 in sub _cmd_ok] * OK [PERMANENTFLAGS (\Answered \Flagged \Draft \Deleted \Seen \Recent $MailFlagBit0 $MailFlagBit1 $MailFlagBit2 $Forwarded Redirected $NotJunk NotJunk \*)]\r\n
[…cpan-lib/Net/IMAP/Simple.pm line 413 in sub _process_cmd] 4 OK [READ-WRITE] SELECT completed (took 1 ms)\r\n
[…cpan-lib/Net/IMAP/Simple.pm line 1276 in sub _cmd_ok] 4 OK [READ-WRITE] SELECT completed (took 1 ms)\r\n
[…cpan-lib/Net/IMAP/Simple.pm line 1251 in sub _send_cmd] 5 EXPUNGE\r\n
[…cpan-lib/Net/IMAP/Simple.pm line 1070 in sub _process_cmd] 5 OK EXPUNGE completed (took 2 ms)\r\n
[…cpan-lib/Net/IMAP/Simple.pm line 1276 in sub _cmd_ok] 5 OK EXPUNGE completed (took 2 ms)\r\n
[…cpan-lib/Net/IMAP/Simple.pm line 879 in sub _send_cmd] 6 EXPUNGE\r\n
[…cpan-lib/Net/IMAP/Simple.pm line 1251 in sub _send_cmd] 7 LOGOUT\r\n
[…cpan-lib/Net/IMAP/Simple.pm line 881 in sub _process_cmd] 6 OK EXPUNGE completed (took 3 ms)\r\n
[…cpan-lib/Net/IMAP/Simple.pm line 1276 in sub _cmd_ok] 6 OK EXPUNGE completed (took 3 ms)\r\n
[…cpan-lib/Net/IMAP/Simple.pm line 1197 in sub _seterrstr] warning unknown return string (id=7): 6 OK EXPUNGE completed (took 3 ms)\r\n
[…cpan-lib/Net/IMAP/Simple.pm line 881 in sub _process_cmd] * BYE\r\n
[…cpan-lib/Net/IMAP/Simple.pm line 1276 in sub _cmd_ok] * BYE\r\n
[…cpan-lib/Net/IMAP/Simple.pm line 881 in sub _process_cmd] 7 OK !!\r\n
[…cpan-lib/Net/IMAP/Simple.pm line 1276 in sub _cmd_ok] 7 OK !!\r\n
IMAPS: Connection to imap.mail.me.com closed.

ERROR: OTOBO-otobo.Console.pl-Maint::PostMaster::MailAccountFetch-94 Perl: 5.36.1 OS: linux Time: Thu Feb 15 15:01:01 2024

Message: CommunicationLog(ID:55519,AccountType:-,AccountID:-,Direction:Incoming,Transport:Email,ObjectLogType:Connection,ObjectLogID:62002)::Kernel::System::MailAccount::IMAP => Could not fetch message ‚1‘, answer from server was empty.

Traceback (16322):
Module: Kernel::System::CommunicationLog::_LogError Line: 563
Module: Kernel::System::CommunicationLog::ObjectLog Line: 321
Module: Kernel::System::MailAccount::IMAP::_Fetch Line: 413
Module: Kernel::System::MailAccount::IMAP::Fetch Line: 112
Module: Kernel::System::MailAccount::MailAccountFetch Line: 572
Module: (eval) Line: 180
Module: Kernel::System::Console::Command::Maint::PostMaster::MailAccountFetch::Run Line: 172
Module: (eval) Line: 480
Module: Kernel::System::Console::BaseCommand::Execute Line: 474
Module: Kernel::System::Console::InterfaceConsole::Run Line: 88
Module: bin/otobo.Console.pl Line: 35

Done.

There’s one email in the folder I’ve wrote for testing, it’s just plain text.

I run the latest Otobo 10.1 on Docker linux.

I’ve posted this already on GitHub (Unable to fetch mails · Issue #2971 · RotherOSS/otobo (github.com)) but as you can see it was closed but not fixed, the issue still persists.