Dovecot-1.1.14 on Mac OS X. Panic: IMAP(user): file cmd-append.c: line 266
(cmd_append_continue_parsing): assertion failed: (ctx->count == uid2 -
uid1 + 1)

Trivially reproducible: $ telnet mailserver 143 a login user password b append inbox

Backtrace: 0 libSystem.B.dylib 0x00007fff8458aa92 __kill + 10 1 libSystem.B.dylib 0x00007fff84606a1c abort + 83 2 imap 0x0000000100069f3e
default_fatal_finish + 70 3 imap 0x0000000100069f8c
i_syslog_fatal_handler + 0 4 imap 0x00000001000696eb i_info + 0 5 imap 0x0000000100001406
cmd_append_continue_parsing + 434 6 imap 0x00000001000017a3 cmd_append + 407 7 imap 0x000000010000677e
client_command_input + 33 8 imap 0x000000010000693f
client_command_input + 482 9 imap 0x0000000100006a3e
client_handle_input + 239 10 imap 0x0000000100006bc2 client_input + 148 11 imap 0x0000000100070f83
io_loop_handler_run + 272 12 imap 0x0000000100070348 io_loop_run + 55 13 imap 0x000000010000db95 main + 1635 14 imap 0x0000000100001010 start + 52