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I have an Ubuntu server running postfix. It is not the mail server for my domain.

Whenever a cron job runs for root, the output mail is not delivered locally, instead it gets sent to root@mydomain.com via the main mail server. This is not what I want.

I want mail for root to either be delivered locally or forwarded to anothermail@anotherdomain.com.

I've tried modifying both ~root/.forward and /etc/aliases (and running newaliases), but nothing helps (I guess these files are only checked when postfix tries to deliver mail locally).

What can I do?

This is /etc/postfix/main.cf:

smtpd_banner = $myhostname ESMTP $mail_name (Ubuntu)
biff = no
append_dot_mydomain = no
readme_directory = no
smtpd_tls_cert_file=/etc/ssl/certs/ssl-cert-snakeoil.pem
smtpd_tls_key_file=/etc/ssl/private/ssl-cert-snakeoil.key
smtpd_use_tls=yes
smtpd_tls_session_cache_database = btree:${data_directory}/smtpd_scache
smtp_tls_session_cache_database = btree:${data_directory}/smtp_scache
myhostname = linux1.mydomain.com
alias_maps = hash:/etc/aliases
alias_database = hash:/etc/aliases
myorigin = /etc/mailname
mydestination = linux1.mydomain.com, localhost.linux1.mydomain.com, localhost
relayhost = my.isps.relayhost.com
mynetworks = 127.0.0.0/8 [::ffff:127.0.0.0]/104 [::1]/128
mailbox_size_limit = 0
recipient_delimiter = +
inet_interfaces = loopback-only

Edit:

When sending mail to root, this goes into /var/log/mail.log:

Mar  7 09:39:17 linux1 postfix/pickup[31381]: F3B9C98025E: uid=1000 from=<ct>
Mar  7 09:39:18 linux1 postfix/cleanup[31556]: F3B9C98025E: message-id=<20130307083917.F3B9C98025E@linux1.mydomain.com>
Mar  7 09:39:18 linux1 postfix/qmgr[28525]: F3B9C98025E: from=<ct@mydomain.com>, size=283, nrcpt=1 (queue active)
Mar  7 09:39:18 linux1 postfix/smtp[31558]: F3B9C98025E: to=<root@mydomain.com>, orig_to=<root>, relay=my.isps.relayhost.com[<IP address omitted>]:25, delay=0.72, delays=0.19/0.02/0.27/0.25, dsn=2.0.0, status=sent (250 Ok: queued as A97F5D8126)
Mar  7 09:39:18 linux1 postfix/qmgr[28525]: F3B9C98025E: removed

The name "ct" is my user name. I generated the above text through this command:

echo test | mail -s test root

The content of /etc/mailname is:

mydomain.com

The contents of /etc/aliases is:

root: anothermail@anotherdomain.com
postmaster:    root

where anothermail@anotherdomain.com is where I would like root's mail to be forwarded to.

The content of /etc/hosts actually surprises me a little:

127.0.0.1 localhost
127.0.1.1 linux1.mylinux.mydomain.com linux1

where "mylinux" is the hostname of a host operating system under which linux1 runs as a virtual machine. I'm not sure how "mylinux" got in there. (But could this really be the reason for my problem?)

  • Could you provide us your postfix logs when you send a mail to root ? – Dom Mar 7 '13 at 7:56
  • I have done so in an edit to the original post. – oz1cz Mar 7 '13 at 8:44
  • Could you give us your /etc/mailname and /etc/aliases files ? Check if /etc/hosts contains the linux1.mydomain.com assigned to 127.0.1.1 – Dom Mar 7 '13 at 13:41
  • I have added the information to the original post. – oz1cz Mar 7 '13 at 15:05
  • According to your logs, the mail has been correctly sent out to your isp smtp relay. I'd ask them (isp) to check my.isps.relayhost.com[<IP address omitted>] logs for any clue (antispam, error, ...) about the problem. – user130370 Mar 7 '13 at 15:16
13

As ususal, check your logs.

In your case, the postfix daemon think the mail is not for it and send it without using /etc/aliases

First check your /etc/hosts file : it should have your machine name corresponding to 127.0.1.1 : 127.0.1.1 linux1.mydomain.com linux1

Check your /etc/mailname too, and it should be consistent.

Check your /etc/aliases to see if root user is sent to another people, and redo the newaliases command.

And it should work !

  • Should that be 127.0.0.1? – Nate Feb 27 '15 at 22:30
  • You can have any address in 127.0.0.0/8, so 127.0.0.1 works well too – Dom Feb 28 '15 at 9:36
  • I had a similar problem while I only wanted to use a smarthost relay to send mails out: "myhostname" had to be "localhost". Anything else skipped the aliases file. – Alex Nov 4 '15 at 22:16
8

If mydestination is empty or does not contain $myhostname then the /etc/aliases will be ignored because postfix thinks the email is not a local delivery and will therefore not apply the local aliases. So, leave mydestination at the default (postconf -d mydestination or remove it from main.cf) and the logs should show the to=<...> as your aliased address.

  • I'm using an external mail server and mydestination must be empty. Otherwise no mail is sent. – Corni Dec 29 '19 at 13:38
1

In some circumstances, (i.e. where all mail gets relayed to an external system), it's easier to just set the MAILTO variable in root's crontab to a real email address. This should pretty much bypass traditional delivery to root and just make it go where you want.

# Root's crontab
MAILTO=someone@example.com
0 0 * * * /usr/bin/somescript
0

There seems to be some issue with opening of /root/.forward by postfix daemon, at least on hardened system (I didn't dig into it). Despite:

# ls -ld / /root /root/.forward
dr-xr-xr-x. 18 root root  236 Dec  4 00:02 /
dr-xr-x--x. 13 root root 4096 Jan  8 17:45 /root
-rw-r--r--.  1 root root   30 Jan  8 14:51 /root/.forward

Child of postfix daemon is not able to access .forward:

7603  open("/etc/passwd", O_RDONLY|O_CLOEXEC) = 16
7603  fstat(16, {st_mode=S_IFREG|0644, st_size=1227, ...}) = 0
7603  mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f86854fb000
7603  read(16, "root:x:0:0:root:/root:/bin/bash\n"..., 4096) = 1227
7603  close(16)                         = 0
7603  munmap(0x7f86854fb000, 4096)      = 0
7603  geteuid()                         = 89
7603  getegid()                         = 89
7603  geteuid()                         = 89
7603  setresuid(-1, 0, -1)              = 0
7603  setresgid(-1, 0, -1)              = 0
7603  setgroups(1, [0])                 = 0
7603  lstat("/root/.forward", 0x7ffc03f84750) = -1 EACCES (Permission denied)

I didn't have time to dig into it... Appending entry to /etc/aliases followed by newaliases works fine.

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