Here is imapsync 2.229 on host forge, a linux system with 1.3/62.7 free GiB of RAM, 11.10% used by processes.
with Perl 5.38.2 and Mail::IMAPClient 3.43
Transfer started at Wednesday 18 February 2026-02-18 10:42:40 -0500 EST
PID is 710983 my PPID is 1104
Log file is LOG_imapsync/2026_02_18_10_42_40_710_tj@jongsma.me_tj.txt ( to change it, use --logfile path ; or use --nolog to turn off logging )
Load is 0.58 0.56 0.76 1/737 on 8 cores
Current directory is /home/johan/clawd
Real user id is johan (uid 1000)
Effective user id is johan (euid 1000)
$RCSfile: imapsync,v $ $Revision: 2.229 $ $Date: 2022/09/14 18:08:24 $ 
Command line used, run by /usr/bin/perl:
/tmp/imapsync --host1 127.0.0.1 --port1 1143 --user1 tj@jongsma.me --password1 MASKED --tls1 --sslargs1 SSL_verify_mode=0 --host2 127.0.0.1 --port2 9993 --user2 tj --password2 MASKED --ssl2 --sslargs2 SSL_verify_mode=0 --exclude All Mail --exclude Starred --exclude Labels --automap
Temp directory is /tmp ( to change it use --tmpdir dirpath )
kill -QUIT 710983 # special behavior: call to sub catch_exit
kill -TERM 710983 # special behavior: call to sub catch_exit
kill -INT 710983 # special behavior: call to sub catch_reconnect
kill -HUP 710983 # special behavior: call to sub catch_print
kill -USR1 710983 # special behavior: call to sub toggle_sleep
File /tmp/imapsync.pid does not exist
PID file is /tmp/imapsync.pid ( to change it, use --pidfile filepath ; to avoid it use --pidfile "" )
Writing my PID 710983 in /tmp/imapsync.pid
Writing also my logfile name in /tmp/imapsync.pid : LOG_imapsync/2026_02_18_10_42_40_710_tj@jongsma.me_tj.txt
Modules version list ( use --no-modulesversion to turn off printing this Perl modules list ):
Authen::NTLM         1.09
CGI                  4.63
Compress::Zlib       2.204
Crypt::OpenSSL::RSA  0.33
Data::Uniqid         0.12
Digest::HMAC_MD5     1.04
Digest::HMAC_SHA1    1.04
Digest::MD5          2.58_01
Encode               3.19
Encode::IMAPUTF7     1.07
File::Copy::Recursive 0.45
File::Spec           3.88
Getopt::Long         2.54
HTML::Entities       3.81
IO::Socket           1.52
IO::Socket::INET     1.52
IO::Socket::INET6    2.73
IO::Socket::IP       0.4101
IO::Socket::SSL      2.085
IO::Tee              0.65
JSON                 4.10
JSON::WebToken       0.10
LWP                  6.76
MIME::Base64         3.16_01
Mail::IMAPClient     3.43
Net::Ping            2.76
Net::SSLeay          1.94
Term::ReadKey        2.38
Test::MockObject     Not installed
Time::HiRes          1.9775
URI::Escape          5.27
Unicode::String      2.10

Info: will resync flags for already transferred messages. Use --noresyncflags to not resync flags.
SSL debug mode level is --debugssl 1 (can be set from 0 meaning no debug to 4 meaning max debug)
Host2: SSL default mode is like --sslargs2 "SSL_verify_mode=0", meaning for host2 SSL_VERIFY_NONE, ie, do not check the server certificate.
Host2: Use --sslargs2 SSL_verify_mode=1 to have SSL_VERIFY_PEER, ie, check the server certificate. of host2
Info: turned ON syncinternaldates, will set the internal dates (arrival dates) on host2 same as host1.
Host1: will try to use LOGIN authentication on host1
Host2: will try to use LOGIN authentication on host2
Host1: imap connection timeout is 120 seconds
Host2: imap connection timeout is 120 seconds
Host1: imap connection keepalive is on on host1. Use --nokeepalive1 to disable it.
Host2: imap connection keepalive is on on host2. Use --nokeepalive2 to disable it.
Host1: IMAP server [127.0.0.1] port [1143] user [tj@jongsma.me]
Host2: IMAP server [127.0.0.1] port [9993] user [tj]
Host1: connecting and login on host1 [127.0.0.1] port [1143] with user [tj@jongsma.me]
Host1 IP address: 127.0.0.1 Local IP address: 127.0.0.1
Host1 banner: * OK [CAPABILITY AUTH=PLAIN ID IDLE IMAP4rev1 MOVE STARTTLS UIDPLUS UNSELECT] Proton Mail Bridge 03.21.02 - gluon session ID 1868
Host1 capability before authentication: AUTH=PLAIN ID IDLE IMAP4rev1 STARTTLS AUTH
Host1: Socket successfully converted to SSL
Host1: success login on [127.0.0.1] with user [tj@jongsma.me] auth [LOGIN] or [LOGIN]
Host2: connecting and login on host2 [127.0.0.1] port [9993] with user [tj]
DEBUG: ...base/IO/Socket.pm:49: local error: IO::Socket::IP configuration failed
Host2 failure: can not open imap connection on host2 [127.0.0.1] with user [tj]: Unable to connect to 127.0.0.1: IO::Socket::IP configuration failed Connection refused
++++ Listing 1 errors encountered during the sync ( avoid this listing with --noerrorsdump ).
Err 1/1: Host2 failure: can not open imap connection on host2 [127.0.0.1] with user [tj]: Unable to connect to 127.0.0.1: IO::Socket::IP configuration failed Connection refused
The most frequent error is ERR_CONNECTION_FAILURE_HOST2. Check that host1 127.0.0.1 on port 9993 is the right IMAP server to be contacted for your mailbox.
Exiting with return value 102 (EXIT_CONNECTION_FAILURE_HOST2) 1/50 nb_errors/max_errors PID 710983
Removing pidfile /tmp/imapsync.pid
Disconnecting from host1 127.0.0.1 user1 tj@jongsma.me
Log file is LOG_imapsync/2026_02_18_10_42_40_710_tj@jongsma.me_tj.txt ( to change it, use --logfile filepath ; or use --nolog to turn off logging )
