Email is cut off

Hi everyone,

I just started to use getmail as a replacement for a Windows based fetcher. It will fetch the emails from the internet and forwards it via sendmail/postfix to our MS Exchange server, filtered with clamav and spamassassin.
It is running as PoC for the first user since two weeks, but yesterday we faced an issue with one email. It was send to the mentioned user and in CC to another user which is still using the old fetcher tool. The user which was using getmail just received an email containing the first three lines and then it was cut off, the other user received the whole mail containing a longer text including the history of the email exchange. Any ideas what could cause this behavior? I couldn't find a proper hint in the logs. Here is the whole entry for this email:

Dec  9 07:10:01 serverXYZ CRON[460663]: (relay) CMD (/usr/bin/getmail --rcfile [email protected] --rcfile [email protected] &> /dev/null)
Dec  9 07:10:01 serverXYZ spamd[375582]: spamd: connection from ::1 [::1]:47170 to port 783, fd 5
Dec  9 07:10:01 serverXYZ spamd[375582]: spamd: setuid to relay succeeded
Dec  9 07:10:01 serverXYZ spamd[375582]: spamd: processing message <messageID> for relay:1001
Dec  9 07:10:02 serverXYZ spamd[375582]: spamd: clean message (1.1/4.0) for relay:1001 in 0.5 seconds, 155186 bytes.
Dec  9 07:10:02 serverXYZ spamd[375582]: spamd: result: . 1 - DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,HTML_MESSAGE,PDS_HP_HELO_NORDNS,RCVD_IN_DNSWL_NONE,RCVD_IN_MSPIKE_H2,RDNS_NONE,SPF_HELO_PASS,SPF_PASS scantime=0.5,size=155186,user=relay,uid=1001,required_score=4.0,rhost=::1,raddr=::1,rport=47170,mid=<messageID>,autolearn=no autolearn_force=no
Dec  9 07:10:02 serverXYZ getmail: msg 334/334 (157415 bytes) msgid 395905161/19584 from <[email protected]> delivered to MDA_external command sendmail ()
Dec  9 07:10:02 serverXYZ postfix/pickup[459649]: 78496311: uid=1001 from=<relay>
Dec  9 07:10:02 serverXYZ postfix/cleanup[460672]: 78496311: message-id=<messageID>
Dec  9 07:10:02 serverXYZ postfix/qmgr[156054]: 78496311: from=<[email protected]>, size=12969, nrcpt=1 (queue active)
Dec  9 07:10:02 serverXYZ postfix/smtp[460674]: 78496311: to=<[email protected]>, relay=10.10.1.18[10.10.1.18]:25, delay=0.21, delays=0.05/0.01/0.01/0.13, dsn=2.6.0, status=sent (250 2.6.0 <messageID> [InternalId=57715770523654, Hostname=target.internal.domain] 14429 bytes in 0.122, 115,466 KB/sec Queued mail for delivery)

Here is the used config:
[retriever]
type = SimpleIMAPRetriever
server =
username =
password =
mailboxes = ("INBOX",)

[destination]
type = MDA_external
path = /usr/sbin/sendmail
arguments = ("-bm", "xyz")
unixfrom = true

[options]
verbose = 1
read_all = false
delete_after = 14
message_log_syslog = true

[filter-1]
type = Filter_external
path = /usr/bin/spamc
arguments = ("-s", "250000", )

[filter-2]
type = Filter_classifier
path = /usr/bin/clamdscan
arguments = ("--stdout", "--no-summary", "-")
exitcodes_drop = (1, )

Hope that someone will be able to give me a hint to avoid that this behavior will be repeated.

Regards,
Niklas