Smtp 435 ошибка

Bobcares.com provides outsourced hosting support to web hosts. As part of our services, we manage the tech support help desk of web hosts, and resolve issues posted by web hosting customers.

Many of our customers use Linux servers that run Exim as their mail server. Exim is usually present in web control panels such as Cpanel, DirectAdmin, Ajenti and more.

A common email error that we see in these servers is 435 Unable to authenticate at present. This is faced by email users when they try to send SMTP authenticated mail through the Exim server either through webmail (eg. Horde) or from an external mail service provider (Eg. Google’s Gmail).

In short, this error happens when Exim is unable to check if the Username and Password given by the mail user is indeed correct.

It can happen due to:

• Failure of service that provides authentication (eg. Dovecot)
• Incorrect mailbox permissions
• User exceeding mail limits
• Incorrect SMTP Port settings at the email user’s client
• Corrupted auth libraries
• Disk quota issues

Let’s take a look at each of these issues one by one, and see how to fix it.

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Before we begin – a word of caution

Many server owners troubleshoot issues by trial and error. That is – Do X. Did it fix it? No? Then do Y.

It is not the best way to resolve issues, because:

• It takes a lot of time to go through all possibilities.
• A command executed without knowing the full impact of it could result in other services failing.
• In case something does go wrong, it’s hard to recover from it without knowing what changes the command made.
• Your server could have custom settings that can conflict with standard commands.

That is why we always recommend our customers to not make changes directly on the server, and instead escalate it to our 24/7 support team.

Our team uses an evidence based approach to solve issues. We look at logs, trace the sequence of events, and then find out exactly where the link is broken. It helps us solve issues faster, and prevent errors.

With that said, let’s now look at the top fixes for this error.

1. Quick fix – Restart POP/IMAP service

In some servers we’ve observed the POP/IMAP service failing to authenticate because of temporary data write issues.

So, a quick fix is to check if the database services are running OK, if the /tmp directory is clear, the disk health is OK, and then restart the POP/IMAP service.

In cPanel servers, this service is DoveCot.

2. Fix mail box permissions

When a login request is sent to POP/IMAP service, the server checks whether the mail directory is in fact accessible. If it is not, the IMAP server gives a fail signal to Exim, and this error will be shown.

So, if this account was recently migrated in, or was un-suspended, or any other recent changes were made, it’ll be a good idea to repair the mailbox permissions.

In cPanel servers, this can be done by:

1. Login to WHM
2. Locate the Email section in the left-side panel
3. Select Repair Mailbox permissions
4. Click Proceed.

3. Check mail limits

Many control panels allow mail limits to be set for each user. If the user has exceeded that limit for the time period (some times due to spamming via his account), no more mails can be sent.

So, look for the mail stats to see if this quota is exceeded.

4. Incorrect SMTP port

Many mail services (such as Google’s Gmail) does not allow outbound connections via port 25.

So, ask the customer if he has set the SMTP port as 25, and if so, to change it to port 587 or 465.

[ You don’t have to lose your sleep to keep your customers happy. Our friendly Hosting Support Specialists are online 24/7/365 to help your customers. ]

5. Corrupted authentication libraries

Exim and Dovecot depends on underlying system libraries to perform authentication functions.

In some servers which was recently upgraded, or otherwise a major change was performed, the libraries are likely to be corrupt.

To fix this, Exim should be re-installed.

In DirectAdmin servers, it can be done using CustomBuild, and in cPanel servers, this can be done with:

# /scripts/eximup –-force

IMPORTANT : This will remove all your customized settings, and could fail if you’ve protected your config file. Get expert assistance if you’re not sure.

6. Disk quota issues

In VPSs the disk space or inode limit could get exceeded causing temporary files and database writes to fail. This in turn results in a failed authentication.

So, if the server is prone to such issues, it’s a good idea to check that as well.

To conclude

“435 Unable to authenticate at present” is a common error in Exim servers. It happens when Exim is unable to authenticate an SMTP user. Today we’ve seen a few common reasons why this could happen. There could be more.

If you need assistance in fixing this error, we’d be glad to help. Click on this link to talk to our experts.

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Модератор: xM

16:38:48 23227 250-SIZE 52428800
16:38:48 23227 250-PIPELINING
16:38:48 23227 250-AUTH PLAIN LOGIN CRAM-MD5
16:38:48 23227 250 HELP
16:38:48 23227 Calling SSL_read(7f7ffc83d000, 7f7ffc872000, 4096)
16:38:48 23227 SMTP<< AUTH CRAM-MD5
16:38:48 23227 dovecot authentication
16:38:48 23227 received: MECH   PLAIN   plaintext
16:38:48 23227 received: MECH   LOGIN   plaintext
16:38:48 23227 received: MECH   DIGEST-MD5      dictionary      active  mutual-auth
16:38:48 23227 received: VERSION        1       0
16:38:48 23227 received: SPID   3122
16:38:48 23227 received: CUID   11
16:38:48 23227 received: DONE
16:38:48 23227 expanding: $auth1
16:38:48 23227    result:
16:38:48 23227 SMTP>> 435 Unable to authenticate at present

16:47:24 12383 250-SIZE 52428800
16:47:24 12383 250-PIPELINING
16:47:24 12383 250-AUTH PLAIN LOGIN CRAM-MD5
16:47:24 12383 250-STARTTLS
16:47:24 12383 250 HELP
16:47:24 12383 SMTP<< AUTH CRAM-MD5
16:47:24 12383 dovecot authentication
16:47:24 12383 received: MECH   PLAIN   plaintext
16:47:24 12383 received: MECH   LOGIN   plaintext
16:47:24 12383 received: MECH   DIGEST-MD5      dictionary      active  mutual-auth
16:47:24 12383 received: VERSION        1       0
16:47:24 12383 received: SPID   21094
16:47:24 12383 received: CUID   10
16:47:24 12383 received: DONE
16:47:24 12383 expanding: $auth1
16:47:24 12383    result:
16:47:24 12383 SMTP>> 435 Unable to authenticate at present

begin authenticators

auth_plain:
driver = dovecot
public_name = PLAIN
server_socket = /var/run/dovecot/auth-client
server_set_id = $auth1

auth_login:
driver = dovecot
public_name = LOGIN
server_socket = /var/run/dovecot/auth-client
server_set_id = $auth1

auth_cram_md5:
driver = dovecot
public_name = CRAM-MD5
server_socket = /var/run/dovecot/auth-client
#server_set_id = $auth2
server_set_id = $auth1

auth default {
mechanisms = plain login digest-md5


  socket listen {
    master {
      # Master socket provides access to userdb information. It's typically
      # used to give Dovecot's local delivery agent access to userdb so it
      # can find mailbox locations.
      path = /var/run/dovecot/auth-master
      mode = 0600
      # Default user/group is the one who started dovecot-auth (root)
      user = mail
      group = mail
    }
    client {
      # The client socket is generally safe to export to everyone. Typical use
      # is to export it to your SMTP server so it can do SMTP AUTH lookups
      # using it.
      path = /var/run/dovecot/auth-client
      mode = 0660
      user = mail
      group = mail
    }
  }



passdb passwd-file {
  args = scheme=cram-md5 /etc/master.passwd
}
user = root
}

butch писал(а): ↑

19.05.2009 11:20

я к сожалению на дебиане экзим не ставил. но:

Rovnyi писал(а): ↑

14.05.2009 17:02

exim_user = mailnull
exim_group = mail

мы имеем указанные в конфиге юзера и группу.
сделай chown -R mailnull.mail на все папки, которыми пользуется экзим. если кнчно такой юзер и группа в системе есть.
на папки права 750
на файлы 640

очень спасибо за за указания, вроде помогло)))). логи екзима перестали выдавать ошибки, теперь пишут что доставляют письма(правда только по локалке). но тут началась история с довекотом. теперь он требует права доступа к mbox. логи выглядят следующим образом:

dovecot: 2009-05-19 19:29:43 Info: IMAP(ilya): Effective uid=1002, gid=1003, home=/home/ilya
dovecot: 2009-05-19 19:29:43 Info: IMAP(ilya): mbox: data=/var/mail//i/ilya:INDEX=/var/indexes//i/ilya
dovecot: 2009-05-19 19:29:43 Info: IMAP(ilya): mbox: INBOX defaulted to /var/mail//i/ilya/inbox
dovecot: 2009-05-19 19:29:43 Info: IMAP(ilya): mbox: root=/var/mail//i/ilya, index=/var/indexes//i/ilya, inbox=/var/mail//i/ilya/inbox
ovecot: 2009-05-19 19:29:43 Info: imap-login: Login: user=<ilya>, method=PLAIN, rip=192.168.0.102, lip=192.168.0.1
dovecot: 2009-05-19 19:29:43 Info: POP3(ilya): Disconnected: Logged out top=0/0, retr=0/0, del=0/0, size=0
dovecot: 2009-05-19 19:29:43 Error: IMAP(ilya): mkdir_parents(/var/indexes//i/ilya/.imap/&BB0ENQQ2BDUEOwQwBEIENQQ7BEwEPQQwBE8- &BD8EPgRHBEIEMA-) failed: Permission denied

пользователь ilya создан на системе, пароли берутся с /etc/passwd. аутглюк ошибок не выдает, отсылает письма, но по локальной сети они не доходят до адресата. из-за недостатка прав на изменения необходимых папок и файлов. насколько я понял из логов довекот не может создать папку indexes в /var. вопрос: что делать с правами? вывод команды

ls -lah /var/
итого 68K
drwxr-xr-x 17 root     root  4,0K Апр  2 15:17 .
drwxr-xr-x 21 root     root  4,0K Май 12 15:29 ..
drwxr-xr-x  2 root     root  4,0K Май 18 11:15 backups
drwxr-xr-x 18 root     root  4,0K Май  1 13:26 cache
drwxr-xr-x  2 root     root  4,0K Окт 22  2008 crash
drwxr-xr-x  2 root     root  4,0K Мар 30 14:54 games
drwxr-xr-x 49 root     root  4,0K Май 14 14:24 lib
drwxrwsr-x  2 root     staff 4,0K Дек  4 15:22 local
drwxrwxrwt  4 root     root  4,0K Май 19 09:09 lock
drwxrwxrwx 16 root     root  4,0K Май 19 09:38 log
drwxrwsrwx  5 mailnull mail  4,0K Май 19 19:46 mail
drwxr-xr-x  2 root     root  4,0K Мар 30 13:44 opt
drwxr-xr-x 19 root     root  4,0K Май 19 18:42 run
drwxr-xr-x 11 root     root  4,0K Май 14 13:53 spool
drwxrwxrwt  4 root     root  4,0K Май 19 11:54 tmp
drwx------  2 root     bin   4,0K Апр  5 11:26 webmin
drwxr-xr-x  2 root     root  4,0K Мар 30 14:49 www
root@server-debian:/home/odmin# ls -lah /var/mail/
итого 508K
drwxrwsrwx  5 root   mail 4,0K Май 19 19:46 .
drwxr-xr-x 17 root   root 4,0K Апр  2 15:17 ..
drwxrwsrwx  3 anton  mail 4,0K Май 19 09:28 a
-rw-rw----  1 andrew mail 3,9K Май 18 10:55 andrew
-rw-rw----  1 anton  mail  23K Май 19 19:25 anton
-rwxrwx---  1 root   mail 251K Апр 25 12:00 BOGUS.odmin.fkfB
drwx--S---  3 denis  mail 4,0K Май 19 09:35 d
-rw-rw----  1 denis  mail  935 Май 18 10:55 denis
drwx--S---  3 ilya   mail 4,0K Май 19 09:28 i
-rw-rw----  1 ilya   mail  37K Май 19 19:24 ilya
-rw-rw----  1 odmin  mail 153K Май 19 19:00 odmin
root@server-debian:/home/odmin# ls -lah /var/mail/i
итого 12K
drwx--S--- 3 ilya mail 4,0K Май 19 09:28 .
drwxrwsrwx 5 root mail 4,0K Май 19 20:00 ..
drwx--S--- 2 ilya mail 4,0K Май 19 19:56 ilya
root@server-debian:/home/odmin# ls -lah /var/mail/i/ilya/
итого 12K
drwx--S--- 2 ilya mail 4,0K Май 19 19:56 .
drwx--S--- 3 ilya mail 4,0K Май 19 09:28 ..
-rw------- 1 ilya mail    0 Май 19 19:16 &BB0ENQQ2BDUEOwQwBEIENQQ7BEwEPQQwBE8- &BD8EPgRHBEIEMA-
-rw------- 1 ilya mail    0 Май 19 09:28 inbox
-rw------- 1 ilya mail   55 Май 19 19:16 .subscriptions

какие же еще права выставлять? я не понимаю уже честно говоря…
З.Ы да, кстати, в конфиге довекота я раскомментил две строки, которые имхо твечают за работу довекота в папках назначения

mail_privileged_group = mail
mail_access_groups = mail

и все равно Permission denied