dovecot - Apr 2016 - Intermittent IMAP Login failures - about 25% fail

New server & just added three domains:
now I see
"dovecot: imap-login: Aborted login (auth failed, 1 attempts in 5 secs):
user=<username.companyname>, method=PLAIN, rip=1.1.1.1, lip=99.99.99.99,
TLS, session=<kw6Y2NYviQBex5Un>"
Plus all Outlook users keep being bounced and finally get in.
I am going to kill all the users soon...

Not too many files open, nor bandwidth, nor load.

Any light/help appreciated.



root at brazil:/var/log# dovecot --version
2.2.9
root at brazil:/var/log# dovecot -n
# 2.2.9: /etc/dovecot/dovecot.conf
# OS: Linux 3.19.0-58-generic x86_64 Ubuntu 14.04.4 LTS
auth_debug_passwords = yes
auth_mechanisms = plain login
mail_location = maildir:~/Maildir
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 {
  driver = pam
}
protocols = imap pop3 pop3
ssl_cert = </etc/dovecot/dovecot.pem
ssl_key = </etc/dovecot/private/dovecot.pem
userdb {
  driver = passwd
}


Thanks

New server & just added three domains:
now I see
"dovecot: imap-login: Aborted login (auth failed, 1 attempts in 5 secs):
user=<username.companyname>, method=PLAIN, rip=1.1.1.1, lip=99.99.99.99,
TLS, session=<kw6Y2NYviQBex5Un>"
Plus all Outlook users keep being bounced and finally get in.

Failure rate is a predictable 25%


I am going to kill all the users soon...

Not too many files open, nor bandwidth, nor load.

Any light/help appreciated.





root at brazil:/var/log# dovecot --version
2.2.9
root at brazil:/var/log# dovecot -n
# 2.2.9: /etc/dovecot/dovecot.conf
# OS: Linux 3.19.0-58-generic x86_64 Ubuntu 14.04.4 LTS
auth_debug_passwords = yes
auth_mechanisms = plain login
mail_location = maildir:~/Maildir
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 {
  driver = pam
}
protocols = imap pop3 pop3
ssl_cert = </etc/dovecot/dovecot.pem
ssl_key = </etc/dovecot/private/dovecot.pem
userdb {
  driver = passwd
}


Thanks

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

On Thu, 7 Apr 2016, Mobile Phone wrote:
> New server & just added three domains:
> now I see
> "dovecot: imap-login: Aborted login (auth failed, 1 attempts in 5
secs):
> user=<username.companyname>, method=PLAIN, rip=1.1.1.1,
lip=99.99.99.99,
> TLS, session=<kw6Y2NYviQBex5Un>"
> Plus all Outlook users keep being bounced and finally get in.
Did you tried to enable auth debug?

http://wiki2.dovecot.org/Debugging/Authentication

- -- 
Steffen Kaiser
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1

iQEVAwUBVwZad3z1H7kL/d9rAQLDGwf/RS54zzxS4P6XxBmwPL2b3iA2YD5a9dHL
+jTs6s5zS0leX8PWcrjES9BoU8pRBRm4IRqJFI5eZeWmhSVvHSe5iAEZ0n8k+MGc
yunHljQLvsNg5EJtxiOf7TLw9k7lJuilKb5WR1aC5gBO0NscxWUIhXHy1uSGOGv8
xtzZPSvmZJcjQWqtVl7NklUy8+jRj42uwtS3Q3G2OhyBR45vpsPQBkeNsYHaITdF
Q+LE6lAaVFuxCoX7d4XQyt+craNq0mNEl3A6DBb41YY6bK+QdXt9ciG1iOAF1aR1
zPRlII0Vt1USX9Jw+B24/f6zfFv5yQ6q/k35o9YO0taot5swtnJBOA==2aRu
-----END PGP SIGNATURE-----