Here’s a ten second snippet from my mail server's log, showing how intense the login frequency was from the attacker, and also how (s)he was "scattering" the login names used which I suspect would be quite hard to filter out using POP's mail_max_userip_connections parameter. The attack lasted from 1:43:39 through a server restart at 1:50:18, and even about a minute later. The attack stopped at 1:51:36 before I was able to add a firewalling rule to my router or to exclude logins from the 163.150/16 subnet from my router [FYI — that's the San Bernadino Country School District, according to http://whois.arin.net/rest/net/NET-163-150-0-0-1/pft ].
Any thoughts on how to block this type of POP attack in Dovecot?
[FYI — I changed my actual server name to 'myserver' and the actual admin name to 'Administrator'.]
Jan 13 13:43:39 myserver dovecot[72]: auth(default): od(root,163.150.246.27): user account: root not enabled for mail
Jan 13 13:43:39 myserver dovecot[72]: auth(default): od[getpwnam_ext](admin,163.150.246.27): No record for user
Jan 13 13:43:39 myserver dovecot[72]: auth(default): od(admin,163.150.246.27): lookup failed for user: admin
Jan 13 13:43:39 myserver dovecot[72]: auth(default): od(webmaster,163.150.246.27): Credentials could not be verified username or password is invalid.
Jan 13 13:43:39 myserver dovecot[72]: auth(default): od[getpwnam_ext](user,163.150.246.27): No record for user
Jan 13 13:43:39 myserver dovecot[72]: auth(default): od(user,163.150.246.27): lookup failed for user: user
Jan 13 13:43:39 myserver dovecot[72]: auth(default): od[getpwnam_ext](test,163.150.246.27): No record for user
Jan 13 13:43:39 myserver dovecot[72]: auth(default): od(test,163.150.246.27): lookup failed for user: test
Jan 13 13:43:40 myserver dovecot[72]: auth(default): od[getpwnam_ext](web,163.150.246.27): No record for user
Jan 13 13:43:40 myserver dovecot[72]: auth(default): od(web,163.150.246.27): lookup failed for user: web
Jan 13 13:43:40 myserver dovecot[72]: auth(default): od(www,163.150.246.27): user account: _www not enabled for mail
Jan 13 13:43:40 myserver dovecot[72]: auth(default): od(administrator,163.150.246.27): user account: Administrator not enabled for mail
Jan 13 13:43:40 myserver dovecot[72]: auth(default): od[getpwnam_ext](oracle,163.150.246.27): No record for user
Jan 13 13:43:40 myserver dovecot[72]: auth(default): od(oracle,163.150.246.27): lookup failed for user: oracle
Jan 13 13:43:40 myserver dovecot[72]: auth(default): od(root,163.150.246.27): user account: root not enabled for mail
Jan 13 13:43:40 myserver dovecot[72]: auth(default): od[getpwnam_ext](admin,163.150.246.27): No record for user
Jan 13 13:43:40 myserver dovecot[72]: auth(default): od(admin,163.150.246.27): lookup failed for user: admin
Jan 13 13:43:40 myserver dovecot[72]: auth(default): od[getpwnam_ext](sybase,163.150.246.27): No record for user
Jan 13 13:43:40 myserver dovecot[72]: auth(default): od(sybase,163.150.246.27): lookup failed for user: sybase
Jan 13 13:43:40 myserver dovecot[72]: auth(default): od[getpwnam_ext](informix,163.150.246.27): No record for user
Jan 13 13:43:40 myserver dovecot[72]: auth(default): od(informix,163.150.246.27): lookup failed for user: informix
Jan 13 13:43:40 myserver dovecot[72]: auth(default): od(root,163.150.246.27): user account: root not enabled for mail
Jan 13 13:43:40 myserver dovecot[72]: auth(default): od(webmaster,163.150.246.27): Credentials could not be verified username or password is invalid.
Jan 13 13:43:40 myserver dovecot[72]: auth(default): od[getpwnam_ext](oracle8,163.150.246.27): No record for user
Jan 13 13:43:40 myserver dovecot[72]: auth(default): od(oracle8,163.150.246.27): lookup failed for user: oracle8
Jan 13 13:43:40 myserver dovecot[72]: auth(default): od(backup,163.150.246.27): user account: backup not enabled for mail
Jan 13 13:43:40 myserver dovecot[72]: auth(default): od(root,163.150.246.27): user account: root not enabled for mail
Jan 13 13:43:40 myserver dovecot[72]: auth(default): od(webmaster,163.150.246.27): Credentials could not be verified username or password is invalid.
Jan 13 13:43:40 myserver dovecot[72]: auth(default): od[getpwnam_ext](lizdy,163.150.246.27): No record for user
Jan 13 13:43:40 myserver dovecot[72]: auth(default): od(lizdy,163.150.246.27): lookup failed for user: lizdy
Jan 13 13:43:40 myserver dovecot[72]: auth(default): od[getpwnam_ext](test,163.150.246.27): No record for user
Jan 13 13:43:40 myserver dovecot[72]: auth(default): od(test,163.150.246.27): lookup failed for user: test
Jan 13 13:43:40 myserver dovecot[72]: auth(default): od[getpwnam_ext](user,163.150.246.27): No record for user
Jan 13 13:43:40 myserver dovecot[72]: auth(default): od(user,163.150.246.27): lookup failed for user: user
Jan 13 13:43:41 myserver dovecot[72]: auth(default): od[getpwnam_ext](web,163.150.246.27): No record for user
Jan 13 13:43:41 myserver dovecot[72]: auth(default): od(web,163.150.246.27): lookup failed for user: web
Jan 13 13:43:41 myserver dovecot[72]: auth(default): od[getpwnam_ext](admin,163.150.246.27): No record for user
Jan 13 13:43:41 myserver dovecot[72]: auth(default): od(admin,163.150.246.27): lookup failed for user: admin
Jan 13 13:43:41 myserver dovecot[72]: auth(default): od(www,163.150.246.27): user account: _www not enabled for mail
Jan 13 13:43:41 myserver dovecot[72]: auth(default): od[getpwnam_ext](server,163.150.246.27): No record for user
Jan 13 13:43:41 myserver dovecot[72]: auth(default): od(server,163.150.246.27): lookup failed for user: server
Jan 13 13:43:41 myserver dovecot[72]: auth(default): od[getpwnam_ext](test,163.150.246.27): No record for user
Jan 13 13:43:41 myserver dovecot[72]: auth(default): od(test,163.150.246.27): lookup failed for user: test
Jan 13 13:43:41 myserver dovecot[72]: auth(default): od[getpwnam_ext](data,163.150.246.27): No record for user
Jan 13 13:43:41 myserver dovecot[72]: auth(default): od(data,163.150.246.27): lookup failed for user: data
Jan 13 13:43:41 myserver dovecot[72]: auth(default): od(administrator,163.150.246.27): user account: Administrator not enabled for mail
Jan 13 13:43:41 myserver dovecot[72]: auth(default): od[getpwnam_ext](web,163.150.246.27): No record for user
Jan 13 13:43:41 myserver dovecot[72]: auth(default): od(web,163.150.246.27): lookup failed for user: web
Jan 13 13:43:41 myserver dovecot[72]: auth(default): od(webmaster,163.150.246.27): Credentials could not be verified username or password is invalid.
Jan 13 13:43:41 myserver dovecot[72]: auth(default): od[getpwnam_ext](user,163.150.246.27): No record for user
Jan 13 13:43:41 myserver dovecot[72]: auth(default): od(user,163.150.246.27): lookup failed for user: user
Jan 13 13:43:41 myserver dovecot[72]: auth(default): od[getpwnam_ext](account,163.150.246.27): No record for user
Jan 13 13:43:41 myserver dovecot[72]: auth(default): od(account,163.150.246.27): lookup failed for user: account
Jan 13 13:43:41 myserver dovecot[72]: auth(default): od(www,163.150.246.27): user account: _www not enabled for mail
Jan 13 13:43:41 myserver dovecot[72]: auth(default): od[getpwnam_ext](oracle,163.150.246.27): No record for user
Jan 13 13:43:41 myserver dovecot[72]: auth(default): od(oracle,163.150.246.27): lookup failed for user: oracle
Jan 13 13:43:41 myserver dovecot[72]: auth(default): od[getpwnam_ext](sybase,163.150.246.27): No record for user
Jan 13 13:43:41 myserver dovecot[72]: auth(default): od(sybase,163.150.246.27): lookup failed for user: sybase
Jan 13 13:43:41 myserver dovecot[72]: auth(default): od[getpwnam_ext](test,163.150.246.27): No record for user
Jan 13 13:43:41 myserver dovecot[72]: auth(default): od(test,163.150.246.27): lookup failed for user: test
Jan 13 13:43:41 myserver dovecot[72]: auth(default): od[getpwnam_ext](access,163.150.246.27): No record for user
Jan 13 13:43:41 myserver dovecot[72]: auth(default): od(access,163.150.246.27): lookup failed for user: access
Jan 13 13:43:41 myserver dovecot[72]: auth(default): od(administrator,163.150.246.27): user account: Administrator not enabled for mail
Jan 13 13:43:41 myserver dovecot[72]: auth(default): od[getpwnam_ext](web,163.150.246.27): No record for user
Jan 13 13:43:41 myserver dovecot[72]: auth(default): od(web,163.150.246.27): lookup failed for user: web
Jan 13 13:43:41 myserver dovecot[72]: auth(default): od[getpwnam_ext](pwrchute,163.150.246.27): No record for user
Jan 13 13:43:41 myserver dovecot[72]: auth(default): od(pwrchute,163.150.246.27): lookup failed for user: pwrchute
Jan 13 13:43:41 myserver dovecot[72]: auth(default): od[getpwnam_ext](oracle,163.150.246.27): No record for user
Jan 13 13:43:41 myserver dovecot[72]: auth(default): od(oracle,163.150.246.27): lookup failed for user: oracle
Jan 13 13:43:41 myserver dovecot[72]: auth(default): od[getpwnam_ext](informix,163.150.246.27): No record for user
Jan 13 13:43:41 myserver dovecot[72]: auth(default): od(informix,163.150.246.27): lookup failed for user: informix
Jan 13 13:43:41 myserver dovecot[72]: auth(default): od(www,163.150.246.27): user account: _www not enabled for mail
Jan 13 13:43:41 myserver dovecot[72]: auth(default): od[getpwnam_ext](sybase,163.150.246.27): No record for user
Jan 13 13:43:41 myserver dovecot[72]: auth(default): od(sybase,163.150.246.27): lookup failed for user: sybase
Jan 13 13:43:41 myserver dovecot[72]: auth(default): od[getpwnam_ext](oracle8,163.150.246.27): No record for user
Jan 13 13:43:41 myserver dovecot[72]: auth(default): od(oracle8,163.150.246.27): lookup failed for user: oracle8
Jan 13 13:43:41 myserver dovecot[72]: auth(default): od(administrator,163.150.246.27): user account: Administrator not enabled for mail
Jan 13 13:43:41 myserver dovecot[72]: auth(default): od[getpwnam_ext](informix,163.150.246.27): No record for user
Jan 13 13:43:41 myserver dovecot[72]: auth(default): od(informix,163.150.246.27): lookup failed for user: informix
Jan 13 13:43:41 myserver dovecot[72]: auth(default): od[getpwnam_ext](test,163.150.246.27): No record for user
Jan 13 13:43:41 myserver dovecot[72]: auth(default): od(test,163.150.246.27): lookup failed for user: test
Jan 13 13:43:41 myserver dovecot[72]: auth(default): od[getpwnam_ext](admin,163.150.246.27): No record for user
Jan 13 13:43:41 myserver dovecot[72]: auth(default): od(admin,163.150.246.27): lookup failed for user: admin
Jan 13 13:43:41 myserver dovecot[72]: auth(default): od(backup,163.150.246.27): user account: backup not enabled for mail
Jan 13 13:43:41 myserver dovecot[72]: auth(default): od[getpwnam_ext](user,163.150.246.27): No record for user
Jan 13 13:43:41 myserver dovecot[72]: auth(default): od(user,163.150.246.27): lookup failed for user: user
Jan 13 13:43:41 myserver dovecot[72]: auth(default): od(webmaster,163.150.246.27): Credentials could not be verified username or password is invalid.
Jan 13 13:43:41 myserver dovecot[72]: auth(default): od(root,163.150.246.27): user account: root not enabled for mail
Jan 13 13:43:41 myserver dovecot[72]: auth(default): od[getpwnam_ext](oracle,163.150.246.27): No record for user
Jan 13 13:43:41 myserver dovecot[72]: auth(default): od(oracle,163.150.246.27): lookup failed for user: oracle
Jan 13 13:43:41 myserver dovecot[72]: auth(default): od[getpwnam_ext](lizdy,163.150.246.27): No record for user
Jan 13 13:43:41 myserver dovecot[72]: auth(default): od(lizdy,163.150.246.27): lookup failed for user: lizdy
Jan 13 13:43:41 myserver dovecot[72]: auth(default): od[getpwnam_ext](oracle8,163.150.246.27): No record for user
Jan 13 13:43:41 myserver dovecot[72]: auth(default): od(oracle8,163.150.246.27): lookup failed for user: oracle8
Jan 13 13:43:41 myserver dovecot[72]: auth(default): od[getpwnam_ext](sybase,163.150.246.27): No record for user
Jan 13 13:43:41 myserver dovecot[72]: auth(default): od(sybase,163.150.246.27): lookup failed for user: sybase
Jan 13 13:43:41 myserver dovecot[72]: auth(default): od(backup,163.150.246.27): user account: backup not enabled for mail
Jan 13 13:43:41 myserver dovecot[72]: auth(default): od[getpwnam_ext](server,163.150.246.27): No record for user
Jan 13 13:43:41 myserver dovecot[72]: auth(default): od(server,163.150.246.27): lookup failed for user: server
Jan 13 13:43:41 myserver dovecot[72]: auth(default): od[getpwnam_ext](user,163.150.246.27): No record for user
Jan 13 13:43:41 myserver dovecot[72]: auth(default): od(user,163.150.246.27): lookup failed for user: user
Jan 13 13:43:41 myserver dovecot[72]: auth(default): od(root,163.150.246.27): user account: root not enabled for mail
Jan 13 13:43:41 myserver dovecot[72]: auth(default): od[getpwnam_ext](admin,163.150.246.27): No record for user
Jan 13 13:43:41 myserver dovecot[72]: auth(default): od(admin,163.150.246.27): lookup failed for user: admin
Jan 13 13:43:41 myserver dovecot[72]: auth(default): od[getpwnam_ext](informix,163.150.246.27): No record for user
Jan 13 13:43:41 myserver dovecot[72]: auth(default): od(informix,163.150.246.27): lookup failed for user: informix
Jan 13 13:43:42 myserver dovecot[72]: auth(default): od[getpwnam_ext](lizdy,163.150.246.27): No record for user
Jan 13 13:43:42 myserver dovecot[72]: auth(default): od(lizdy,163.150.246.27): lookup failed for user: lizdy
Jan 13 13:43:42 myserver dovecot[72]: auth(default): od[getpwnam_ext](admin,163.150.246.27): No record for user
Jan 13 13:43:42 myserver dovecot[72]: auth(default): od(admin,163.150.246.27): lookup failed for user: admin
Jan 13 13:43:42 myserver dovecot[72]: auth(default): od[getpwnam_ext](data,163.150.246.27): No record for user
Jan 13 13:43:42 myserver dovecot[72]: auth(default): od(data,163.150.246.27): lookup failed for user: data
Jan 13 13:43:42 myserver dovecot[72]: auth(default): od[getpwnam_ext](oracle8,163.150.246.27): No record for user
Jan 13 13:43:42 myserver dovecot[72]: auth(default): od(oracle8,163.150.246.27): lookup failed for user: oracle8
Jan 13 13:43:44 myserver dovecot[72]: auth(default): od(webmaster,163.150.246.27): Credentials could not be verified username or password is invalid.
Jan 13 13:43:44 myserver dovecot[72]: auth(default): od(backup,163.150.246.27): user account: backup not enabled for mail
Jan 13 13:43:44 myserver dovecot[72]: auth(default): od[getpwnam_ext](user,163.150.246.27): No record for user
Jan 13 13:43:44 myserver dovecot[72]: auth(default): od(user,163.150.246.27): lookup failed for user: user
Jan 13 13:43:44 myserver dovecot[72]: auth(default): od[getpwnam_ext](access,163.150.246.27): No record for user
Jan 13 13:43:44 myserver dovecot[72]: auth(default): od(access,163.150.246.27): lookup failed for user: access
Jan 13 13:43:44 myserver dovecot[72]: auth(default): od[getpwnam_ext](pwrchute,163.150.246.27): No record for user
Jan 13 13:43:44 myserver dovecot[72]: auth(default): od(pwrchute,163.150.246.27): lookup failed for user: pwrchute
Jan 13 13:43:44 myserver dovecot[72]: auth(default): od[getpwnam_ext](server,163.150.246.27): No record for user
Jan 13 13:43:44 myserver dovecot[72]: auth(default): od(server,163.150.246.27): lookup failed for user: server
Jan 13 13:43:44 myserver dovecot[72]: auth(default): od[getpwnam_ext](server,163.150.246.27): No record for user
Jan 13 13:43:44 myserver dovecot[72]: auth(default): od(server,163.150.246.27): lookup failed for user: server
Jan 13 13:43:44 myserver dovecot[72]: auth(default): od[getpwnam_ext](data,163.150.246.27): No record for user
Jan 13 13:43:44 myserver dovecot[72]: auth(default): od(data,163.150.246.27): lookup failed for user: data
Jan 13 13:43:44 myserver dovecot[72]: auth(default): od[getpwnam_ext](lizdy,163.150.246.27): No record for user
Jan 13 13:43:44 myserver dovecot[72]: auth(default): od(lizdy,163.150.246.27): lookup failed for user: lizdy
Jan 13 13:43:44 myserver dovecot[72]: auth(default): od(root,163.150.246.27): user account: root not enabled for mail
Jan 13 13:43:44 myserver dovecot[72]: auth(default): od[getpwnam_ext](account,163.150.246.27): No record for user
Jan 13 13:43:44 myserver dovecot[72]: auth(default): od(account,163.150.246.27): lookup failed for user: account
Jan 13 13:43:44 myserver dovecot[72]: auth(default): od[getpwnam_ext](test,163.150.246.27): No record for user
Jan 13 13:43:44 myserver dovecot[72]: auth(default): od(test,163.150.246.27): lookup failed for user: test
Jan 13 13:43:44 myserver dovecot[72]: auth(default): od[getpwnam_ext](web,163.150.246.27): No record for user
Jan 13 13:43:44 myserver dovecot[72]: auth(default): od(web,163.150.246.27): lookup failed for user: web
Jan 13 13:43:44 myserver dovecot[72]: auth(default): od[getpwnam_ext](access,163.150.246.27): No record for user
Jan 13 13:43:44 myserver dovecot[72]: auth(default): od(access,163.150.246.27): lookup failed for user: access
Jan 13 13:43:44 myserver dovecot[72]: auth(default): od[getpwnam_ext](admin,163.150.246.27): No record for user
Jan 13 13:43:44 myserver dovecot[72]: auth(default): od(admin,163.150.246.27): lookup failed for user: admin
Jan 13 13:43:44 myserver dovecot[72]: auth(default): od[getpwnam_ext](account,163.150.246.27): No record for user
Jan 13 13:43:44 myserver dovecot[72]: auth(default): od(account,163.150.246.27): lookup failed for user: account
Jan 13 13:43:44 myserver dovecot[72]: auth(default): od[getpwnam_ext](data,163.150.246.27): No record for user
Jan 13 13:43:44 myserver dovecot[72]: auth(default): od(data,163.150.246.27): lookup failed for user: data
Jan 13 13:43:44 myserver dovecot[72]: auth(default): od(www,163.150.246.27): user account: _www not enabled for mail
Jan 13 13:43:44 myserver dovecot[72]: auth(default): od[getpwnam_ext](admin,163.150.246.27): No record for user
Jan 13 13:43:44 myserver dovecot[72]: auth(default): od(admin,163.150.246.27): lookup failed for user: admin
Jan 13 13:43:44 myserver dovecot[72]: auth(default): od(administrator,163.150.246.27): user account: Administrator not enabled for mail
Jan 13 13:43:44 myserver dovecot[72]: auth(default): od(www,163.150.246.27): user account: _www not enabled for mail
Jan 13 13:43:44 myserver dovecot[72]: auth(default): od[getpwnam_ext](oracle8,163.150.246.27): No record for user
Jan 13 13:43:44 myserver dovecot[72]: auth(default): od(oracle8,163.150.246.27): lookup failed for user: oracle8
Jan 13 13:43:44 myserver dovecot[72]: auth(default): od[getpwnam_ext](oracle,163.150.246.27): No record for user
Jan 13 13:43:44 myserver dovecot[72]: auth(default): od(oracle,163.150.246.27): lookup failed for user: oracle
Jan 13 13:43:44 myserver dovecot[72]: auth(default): od(administrator,163.150.246.27): user account: Administrator not enabled for mail
Jan 13 13:43:44 myserver dovecot[72]: auth(default): od[getpwnam_ext](oracle8,163.150.246.27): No record for user
Jan 13 13:43:44 myserver dovecot[72]: auth(default): od(oracle8,163.150.246.27): lookup failed for user: oracle8
Jan 13 13:43:46 myserver dovecot[72]: auth(default): od(webmaster,163.150.246.27): Credentials could not be verified username or password is invalid.
Jan 13 13:43:48 myserver dovecot[72]: auth(default): od[getpwnam_ext](oracle,163.150.246.27): No record for user
Jan 13 13:43:48 myserver dovecot[72]: auth(default): od(oracle,163.150.246.27): lookup failed for user: oracle
Jan 13 13:43:48 myserver dovecot[72]: auth(default): od[getpwnam_ext](data,163.150.246.27): No record for user
Jan 13 13:43:48 myserver dovecot[72]: auth(default): od(data,163.150.246.27): lookup failed for user: data
Jan 13 13:43:48 myserver dovecot[72]: auth(default): od[getpwnam_ext](lizdy,163.150.246.27): No record for user
Jan 13 13:43:48 myserver dovecot[72]: auth(default): od(lizdy,163.150.246.27): lookup failed for user: lizdy
Jan 13 13:43:48 myserver dovecot[72]: auth(default): od[getpwnam_ext](admin,163.150.246.27): No record for user
Jan 13 13:43:48 myserver dovecot[72]: auth(default): od(admin,163.150.246.27): lookup failed for user: admin
Jan 13 13:43:48 myserver dovecot[72]: auth(default): od(backup,163.150.246.27): user account: backup not enabled for mail
Jan 13 13:43:48 myserver dovecot[72]: auth(default): od[getpwnam_ext](user,163.150.246.27): No record for user
Jan 13 13:43:48 myserver dovecot[72]: auth(default): od(user,163.150.246.27): lookup failed for user: user
Jan 13 13:43:48 myserver dovecot[72]: auth(default): od[getpwnam_ext](admin,163.150.246.27): No record for user
Jan 13 13:43:48 myserver dovecot[72]: auth(default): od(admin,163.150.246.27): lookup failed for user: admin
Jan 13 13:43:48 myserver dovecot[72]: auth(default): od[getpwnam_ext](test,163.150.246.27): No record for user
Jan 13 13:43:48 myserver dovecot[72]: auth(default): od(test,163.150.246.27): lookup failed for user: test
Jan 13 13:43:48 myserver dovecot[72]: auth(default): od[getpwnam_ext](web,163.150.246.27): No record for user
Jan 13 13:43:48 myserver dovecot[72]: auth(default): od(web,163.150.246.27): lookup failed for user: web
Jan 13 13:43:48 myserver dovecot[72]: auth(default): od[getpwnam_ext](account,163.150.246.27): No record for user
Jan 13 13:43:48 myserver dovecot[72]: auth(default): od(account,163.150.246.27): lookup failed for user: account
Jan 13 13:43:48 myserver dovecot[72]: auth(default): od(www,163.150.246.27): user account: _www not enabled for mail
Jan 13 13:43:48 myserver dovecot[72]: auth(default): od[getpwnam_ext](admin,163.150.246.27): No record for user
Jan 13 13:43:48 myserver dovecot[72]: auth(default): od(admin,163.150.246.27): lookup failed for user: admin
Jan 13 13:43:48 myserver dovecot[72]: auth(default): od(backup,163.150.246.27): user account: backup not enabled for mail
Jan 13 13:43:48 myserver dovecot[72]: auth(default): od[getpwnam_ext](oracle8,163.150.246.27): No record for user
Jan 13 13:43:48 myserver dovecot[72]: auth(default): od(oracle8,163.150.246.27): lookup failed for user: oracle8
Jan 13 13:43:48 myserver dovecot[72]: auth(default): od[getpwnam_ext](web,163.150.246.27): No record for user
Jan 13 13:43:48 myserver dovecot[72]: auth(default): od(web,163.150.246.27): lookup failed for user: web
Jan 13 13:43:48 myserver dovecot[72]: auth(default): od[getpwnam_ext](web,163.150.246.27): No record for user
Jan 13 13:43:48 myserver dovecot[72]: auth(default): od(web,163.150.246.27): lookup failed for user: web
Jan 13 13:43:48 myserver dovecot[72]: auth(default): od[getpwnam_ext](informix,163.150.246.27): No record for user
Jan 13 13:43:48 myserver dovecot[72]: auth(default): od(informix,163.150.246.27): lookup failed for user: informix
Jan 13 13:43:48 myserver dovecot[72]: auth(default): od[getpwnam_ext](oracle,163.150.246.27): No record for user
Jan 13 13:43:48 myserver dovecot[72]: auth(default): od(oracle,163.150.246.27): lookup failed for user: oracle
Jan 13 13:43:48 myserver dovecot[72]: auth(default): od[getpwnam_ext](test,163.150.246.27): No record for user
Jan 13 13:43:48 myserver dovecot[72]: auth(default): od(test,163.150.246.27): lookup failed for user: test
Jan 13 13:43:48 myserver dovecot[72]: auth(default): od[getpwnam_ext](lizdy,163.150.246.27): No record for user
Jan 13 13:43:48 myserver dovecot[72]: auth(default): od(lizdy,163.150.246.27): lookup failed for user: lizdy
Jan 13 13:43:48 myserver dovecot[72]: auth(default): od(backup,163.150.246.27): user account: backup not enabled for mail
Jan 13 13:43:48 myserver dovecot[72]: auth(default): od(www,163.150.246.27): user account: _www not enabled for mail
Jan 13 13:43:48 myserver dovecot[72]: auth(default): od[getpwnam_ext](sybase,163.150.246.27): No record for user
Jan 13 13:43:48 myserver dovecot[72]: auth(default): od(sybase,163.150.246.27): lookup failed for user: sybase
Jan 13 13:43:48 myserver dovecot[72]: auth(default): od(administrator,163.150.246.27): user account: Administrator not enabled for mail
Jan 13 13:43:48 myserver dovecot[72]: auth(default): od(root,163.150.246.27): user account: root not enabled for mail
Jan 13 13:43:48 myserver dovecot[72]: auth(default): od[getpwnam_ext](sybase,163.150.246.27): No record for user
Jan 13 13:43:48 myserver dovecot[72]: auth(default): od(sybase,163.150.246.27): lookup failed for user: sybase
Jan 13 13:43:48 myserver dovecot[72]: auth(default): od[getpwnam_ext](informix,163.150.246.27): No record for user
Jan 13 13:43:48 myserver dovecot[72]: auth(default): od(informix,163.150.246.27): lookup failed for user: informix
Jan 13 13:43:48 myserver dovecot[72]: auth(default): od[getpwnam_ext](sybase,163.150.246.27): No record for user
Jan 13 13:43:48 myserver dovecot[72]: auth(default): od(sybase,163.150.246.27): lookup failed for user: sybase
Jan 13 13:43:48 myserver dovecot[72]: auth(default): od[getpwnam_ext](server,163.150.246.27): No record for user
Jan 13 13:43:48 myserver dovecot[72]: auth(default): od(server,163.150.246.27): lookup failed for user: server
Jan 13 13:43:48 myserver dovecot[72]: auth(default): od(www,163.150.246.27): user account: _www not enabled for mail