Good afternoon

I have been using Dovecot with great success for several months now with one problem:

I have received several messages (3 to date out of a much larger number) which cause Dovecot LMTP to drop the connection with sendmail after only receiving the first part of the message.

Dovecot saves the first part to INBOX, and then drops the link with sendmail as it sees the rest of the data from sendmail as new (and invalid) commands

Sendmail sees the delivery as unsuccessful and requeues the message, so the cycle continues until i kill the queue

These messages are all Multipart MIME

I have attached an extract from the log which shows the above sequence

Finally, I have kept one such message from the sendmail queue (df and qf) should this be useful, but prefer not to post here as not sanitised 

Any help in correcting my configuration would be appreciated.

Thanks

Steve


MAIL LOG extract
-------------------------

Dec  9 12:00:10 phone dovecot[179]: lmtp(20774): Connect from local
Dec  9 12:00:10 phone sm-mta-rx[20764]: STARTTLS=client, relay=localhost, version=TLSv1.3, verify=OK, cipher=TLS_AES_256_GCM_SHA384, bits=256/256
Dec  9 12:00:10 phone dovecot[179]: lmtp(20775): Connect from local
Dec  9 12:00:10 phone sm-mta-rx[20763]: STARTTLS=client, relay=localhost, version=TLSv1.3, verify=OK, cipher=TLS_AES_256_GCM_SHA384, bits=256/256
Dec  9 12:00:10 phone dovecot[179]: lmtp(*********)<20775><8EieKDqu0F8nUQAA0J78UA>: msgid=<39113a86-fdbb-4cea-b1c3-d225dff93328@info.ameli.fr>: saved mail to INBOX
Dec  9 12:00:10 phone dovecot[179]: lmtp(20775): Disconnect from local: Too many invalid commands. (state=READY)
Dec  9 12:00:10 phone sm-mta-rx[20763]: STARTTLS: write error=syscall error (-1), errno=32, get_error=error:00000000:lib(0):func(0):reason(0), retry=1, ssl_err=5
Dec  9 12:00:10 phone sm-mta-rx[20763]: 0B89mOON016803: SYSERR(root): timeout writing message to localhost: Broken pipe
Dec  9 12:00:10 phone sm-mta-rx[20763]: 0B89mOON016803:   0: fl=0x0, mode=20666: CHR: dev=30/1306024, ino=301, nlink=1, u/gid=0/0, size=0
Dec  9 12:00:10 phone sm-mta-rx[20763]: 0B89mOON016803:   1: fl=0x1, mode=20666: CHR: dev=30/1306024, ino=301, nlink=1, u/gid=0/0, size=0
Dec  9 12:00:10 phone sm-mta-rx[20763]: 0B89mOON016803:   2: fl=0x1, mode=20666: CHR: dev=30/1306024, ino=301, nlink=1, u/gid=0/0, size=0
Dec  9 12:00:10 phone sm-mta-rx[20763]: 0B89mOON016803:   3: fl=0x4002, mode=100600: dev=1/2, ino=26089780, nlink=1, u/gid=0/23, size=2041
Dec  9 12:00:10 phone sm-mta-rx[20763]: 0B89mOON016803:   4: fl=0x0, mode=20666: CHR: dev=30/1306024, ino=575, nlink=1, u/gid=0/0, size=0
Dec  9 12:00:10 phone sm-mta-rx[20763]: 0B89mOON016803:   5: fl=0x2, mode=140666: SOCK localhost->[[UNIX: /var/run/mDNSResponder]]
Dec  9 12:00:10 phone sm-mta-rx[20763]: 0B89mOON016803:   6: fl=0x0, mode=100640: dev=1/2, ino=25887976, nlink=1, u/gid=0/23, size=12288
Dec  9 12:00:10 phone sm-mta-rx[20763]: 0B89mOON016803:   7: fl=0x0, mode=100640: dev=1/2, ino=25887976, nlink=1, u/gid=0/23, size=12288
Dec  9 12:00:10 phone sm-mta-rx[20763]: 0B89mOON016803:   8: fl=0x0, mode=100600: dev=1/2, ino=26088246, nlink=1, u/gid=0/23, size=58024
Dec  9 12:00:10 phone sm-mta-rx[20763]: 0B89mOON016803:   9: fl=0x6, mode=140444: SOCK localhost->(Invalid argument)
Dec  9 12:00:10 phone sm-mta-rx[20763]: 0B89mOON016803:  10: fl=0x6, mode=140444: SOCK localhost->(Invalid argument)
Dec  9 12:00:10 phone sm-mta-rx[20763]: 0B89mOON016803:  11: fl=0x0, mode=100640: dev=1/2, ino=25768590, nlink=1, u/gid=0/23, size=12288
Dec  9 12:00:10 phone sm-mta-rx[20763]: 0B89mOON016803:  12: fl=0x0, mode=100640: dev=1/2, ino=25768590, nlink=1, u/gid=0/23, size=12288
Dec  9 12:00:10 phone sm-mta-rx[20763]: 0B89mOON016803: MCI@0x0: NULL
Dec  9 12:00:10 phone sm-mta-rx[20763]: 0B89mOON016803: MCI@0x7fae2c814818: flags=26404c<CACHED,ESMTP,8BITMIME,INMIME,ENHSTAT,PIPELINED,TLSACT>, errno=32, herrno=0, exitstat=75, state=8, pid=0, maxsize=0, phase=client DATA 354, mailer=dovecot, status=4.4.2, rstatus=(null), host=localhost, lastuse=Wed Dec  9 12:00:10 2020\n
Dec  9 12:00:10 phone sm-mta-rx[20763]: 0B89mOON016803: to=<s****************>, delay=1+01:11:31, xdelay=00:00:00, mailer=dovecot, pri=4787366, relay=localhost, dsn=4.4.2, reply=75, stat=Deferred


######################*****##############
### DOVECOT Mailer specification ###
##################*****##################
Mdovecot, P=[IPC], F=zDFMPhnul59,
        S=EnvFromSMTP/HdrFromSMTP, R=EnvToSMTP/HdrFromSMTP,
        T=DNS/RFC822/X-Unix,
        A=FILE /var/run/dovecot/lmtp



dovecot -n
—————

# 2.3.11.3 (502c39af9): /usr/local/etc/dovecot/dovecot.conf
# Pigeonhole version 0.5.11 (d71e0372)
doveconf: Warning: service auth { client_limit=100 } is lower than required under max. load (300)
doveconf: Warning: service anvil { client_limit=100 } is lower than required under max. load (203)
# OS: Darwin 15.6.0 x86_64  
# Hostname: ***************
doveconf: Error: t_readlink(/var/run/dovecot//dovecot.conf) failed: readlink() failed: Permission denied
auth_mechanisms = cram-md5
auth_username_format = %Ln
base_dir = /var/run/dovecot/
default_client_limit = 100
default_internal_group = _dovecot
default_internal_user = _dovecot
default_login_user = _dovenull
hostname =*****************
lda_mailbox_autocreate = yes
mail_gid = 530
mail_home = /var/mail/%d/%n
mail_location = sdbox:~/dbox
mail_uid = 530
managesieve_notify_capability = mailto
managesieve_sieve_capability = fileinto reject envelope encoded-character vacation subaddress comparator-i;ascii-numeric relational regex imap4flags copy include variables body enotify environment mailbox date index ihave duplicate mime foreverypart extracttext
namespace inbox {
  inbox = yes
  location = 
  mailbox Drafts {
    special_use = \Drafts
  }
  mailbox Junk {
    special_use = \Junk
  }
  mailbox Sent {
    special_use = \Sent
  }
  mailbox "Sent Messages" {
    special_use = \Sent
  }
  mailbox Trash {
    special_use = \Trash
  }
  prefix = 
}
passdb {
  args = scheme=SSHA256 username_format=%u /usr/local/etc/dovecot/users
  driver = passwd-file
}
plugin {
  sieve = file:~/sieve;active=~/.dovecot.sieve
}
postmaster_address = postmaster
protocols = imap lmtp
service auth {
  unix_listener auth-userdb {
    group = mailusers
    mode = 0777
    user = _dovecot
  }