SIGABRT when fetching encrypted mail with getmail

[Peter Nabbefeld]

Hello,

I'm stuck with receiving an encrypted email from IMAP server. My getmail 
configuration is (getmail --dump):

getmail configuration:
   getmail version 5.6
   Python version 2.7.15 (default, Jun 27 2018, 13:05:28)
[GCC 8.1.1 20180531]
   retriever:  SimpleIMAPSSLRetriever(ca_certs="None", certfile="None", 
getmaildir="/home/peter/.getmail/", keyfile="None", 
mailboxes="('ALL',)", move_on_delete="None", password="*", 
password_command="()", port="993", record_mailbox="True", 
server="imap.gmx.net", ssl_cert_hostname="None", ssl_ciphers="None", 
ssl_fingerprints="()", ssl_version="None", timeout="180", 
use_cram_md5="False", use_kerberos="False", use_peek="True", 
use_xoauth2="False", username="peter.nabbefeld at gmx.de")
   destination:  MDA_external(allow_root_commands="False", 
arguments="('-e', '-d', 'peter.nabbefeld at gmx.de')", command="deliver", 
group="vmail", ignore_stderr="False", path="/usr/lib/dovecot/deliver", 
unixfrom="False", user="vmail")
   options:
     delete : True
     delete_after : 0
     delete_bigger_than : 0
     delivered_to : False
     fingerprint : False
     logfile : logfile(filename="~/.getmail/log")
     max_bytes_per_session : 0
     max_message_size : 0
     max_messages_per_session : 0
     message_log : ~/.getmail/log
     message_log_syslog : False
     message_log_verbose : False
     read_all : True
     received : False
     verbose : 1


dovecot.log:

Oct 26 07:41:20 
lda(peter.nabbefeld at gmx.de)<24607><UvPzGACp0lsfYAAA7IIYzw>: Panic: file 
istream-crlf.c: line 24 (i_stream_crlf_read_common): assertion failed: 
(ret != -2)
Oct 26 07:41:20 
lda(peter.nabbefeld at gmx.de)<24607><UvPzGACp0lsfYAAA7IIYzw>: Error: Raw 
backtrace: /usr/lib/dovecot/libdovecot.so.0(+0xe8374) [0x7f9ae5706374] 
-> /usr/lib/dovecot/libdovecot.so.0(+0xe83b1) [0x7f9ae57063b1] -> 
/usr/lib/dovecot/libdovecot.so.0(+0x44312) [0x7f9ae5662312] -> 
/usr/lib/dovecot/libdovecot.so.0(+0x4693f) [0x7f9ae566493f] -> 
/usr/lib/dovecot/libdovecot.so.0(+0xf98b6) [0x7f9ae57178b6] -> 
/usr/lib/dovecot/libdovecot.so.0(i_stream_read_memarea+0x81) 
[0x7f9ae5713a31] -> /usr/lib/dovecot/libdovecot.so.0(i_stream_read+0x36) 
[0x7f9ae5713c56] -> /usr/lib/dovecot/libdovecot.so.0(+0xfebf8) 
[0x7f9ae571cbf8] -> 
/usr/lib/dovecot/libdovecot.so.0(i_stream_read_memarea+0x81) 
[0x7f9ae5713a31] -> /usr/lib/dovecot/libdovecot.so.0(i_stream_read+0x36) 
[0x7f9ae5713c56] -> 
/usr/lib/dovecot/libdovecot.so.0(i_stream_read_data+0x4c) 
[0x7f9ae57146ec] -> 
/usr/lib/dovecot/libdovecot.so.0(io_stream_copy+0x8a) [0x7f9ae572ec2a] 
-> /usr/lib/dovecot/libdovecot.so.0(+0x112c12) [0x7f9ae5730c12] -> 
/usr/lib/dovecot/libdovecot.so.0(o_stream_send_istream+0x4f) 
[0x7f9ae572e8bf] -> 
/usr/lib/dovecot/libdovecot-storage.so.0(index_storage_save_continue+0x2e) 
[0x7f9ae58a965e] -> 
/usr/lib/dovecot/libdovecot-storage.so.0(maildir_save_continue+0x27) 
[0x7f9ae58480f7] -> 
/usr/lib/dovecot/libdovecot-storage.so.0(mailbox_save_continue+0x44) 
[0x7f9ae5819fb4] -> 
/usr/lib/dovecot/libdovecot-storage.so.0(mail_storage_copy+0xf8) 
[0x7f9ae580b488] -> 
/usr/lib/dovecot/libdovecot-storage.so.0(maildir_copy+0x59) 
[0x7f9ae5843ea9] -> /usr/lib/dovecot/libdovecot-lda.so.0(+0x3dfc) 
[0x7f9ae593bdfc] -> 
/usr/lib/dovecot/modules/lib20_fts_plugin.so(+0x10d7c) [0x7f9ae53b0d7c] 
-> /usr/lib/dovecot/libdovecot-storage.so.0(+0x58541) [0x7f9ae581a541] 
-> /usr/lib/dovecot/libdovecot-sieve.so.0(+0x4e745) [0x7f9ae3136745] -> 
/usr/lib/dovecot/libdovecot-sieve.so.0(sieve_result_execute+0x50d) 
[0x7f9ae312c0ad] -> /usr/lib/dovecot/libdovecot-sieve.so.0(+0x57139) 
[0x7f9ae313f139] -> 
/usr/lib/dovecot/libdovecot-sieve.so.0(sieve_multiscript_run+0xa2) 
[0x7f9ae3140302] -> 
/usr/lib/dovecot/modules/lib90_sieve_plugin.so(+0x3d49) [0x7f9ae5609d49] 
-> /usr/lib/dovecot/libdovecot-lda.so.0(mail_deliver+0xf9) [0x7f9ae593d219]

dovecot --version
2.3.3 (dcead646b)

For me, it semms like there's a CRLF expected, but probably it cannot be 
detected correctly, since the mail is encrypted - but that's only my 
guess ...

Any idea how to fix that?

Kind regards

Peter