{"id":316,"date":"2012-11-02T15:13:47","date_gmt":"2012-11-02T15:13:47","guid":{"rendered":"http:\/\/nicholshayes.co.uk\/blog\/?p=316"},"modified":"2015-04-10T09:01:21","modified_gmt":"2015-04-10T09:01:21","slug":"simple-local-only-mail","status":"publish","type":"post","link":"http:\/\/nicholshayes.co.uk\/blog\/?p=316","title":{"rendered":"Simple local only mail"},"content":{"rendered":"

I’m working on an application that needs to send notifications via email, and I want to be able to test it in the development environment. In the past, I’ve either been able to set up a small Windows mail server (hMailServer<\/a> is great for this) or just use my standard email account. However, I’m a little restricted in my current environment, and working in a virtual machine. What I really need is a local-only mail solution that will work on my Xubuntu VM.<\/p>\n

In the past I’ve shied away from setting up a mail server on Linux. I failed miserably to set up sendmail in the past. Today I decided to try postfix, and found it very easy to set up a system to work the way I wanted it to.<\/p>\n

Being lazy, I just used the Ubuntu software centre to install postfix. The installation process popped up a config screen, and I selected the local only option. Looking at the postfix documentation<\/a>, I came up with this configuration (etc\/postfix\/main.cf):<\/p>\n

myorigin = localhost
\n
\nsmtpd_banner = $myhostname ESMTP $mail_name (Ubuntu)
\nbiff = no
\n
\n# appending .domain is the MUA's job.
\nappend_dot_mydomain = no
\n
\n# Uncomment the next line to generate "delayed mail" warnings
\n#delay_warning_time = 4h
\n
\nreadme_directory = no
\n
\n# TLS parameters
\nsmtpd_tls_cert_file=\/etc\/ssl\/certs\/ssl-cert-snakeoil.pem
\nsmtpd_tls_key_file=\/etc\/ssl\/private\/ssl-cert-snakeoil.key
\nsmtpd_use_tls=yes
\nsmtpd_tls_session_cache_database = btree:${data_directory}\/smtpd_scache
\nsmtp_tls_session_cache_database = btree:${data_directory}\/smtp_scache
\n
\n# See \/usr\/share\/doc\/postfix\/TLS_README.gz in the postfix-doc package for
\n# information on enabling SSL in the smtp client.
\n
\nmyhostname = localhost
\nalias_maps = hash:\/etc\/aliases
\nalias_database = hash:\/etc\/aliases
\nmydestination = robvm, localhost.localdomain, localhost
\nrelayhost =
\nmynetworks = 127.0.0.0\/8 [::ffff:127.0.0.0]\/104 [::1]\/128
\nmailbox_size_limit = 0
\nrecipient_delimiter = +
\ninet_interfaces = loopback-only
\ndefault_transport = error
\nrelay_transport = error<\/div><\/div>\n

I restarted postfix (‘sudo postfix reload’) and was then able to test (see this<\/a>)<\/p>\n

telnet localhost 25
\nTrying 127.0.0.1...
\nConnected to localhost.
\nEscape character is '^]'.
\n220 localhost ESMTP Postfix (Ubuntu)
\nhelo localhost
\n250 localhost
\nmail from: rob@localhost
\n250 2.1.0 Ok
\nrcpt to:rob@localhost
\n250 2.1.5 Ok
\ndata
\n354 End data with .
\nHello there
\n.
\n250 2.0.0 Ok: queued as E8B7960091C
\nquit
\n221 2.0.0 Bye
\nConnection closed by foreign host.<\/div><\/div>\n

That worked fine, but I wasn’t sure where the email was going. I needed a client.<\/p>\n

I first tried the default email client, which was Thunderbird. However, the configuration seemed to expect an internet mail server and I gave up on that idea pretty quickly.<\/p>\n

Claws<\/a> to the rescue. This mail client is easy to install via the software centre. The main issue was getting the basic settings right. These worked for me:<\/p>\n

\"\"<\/a>

Claws mail client account preferences<\/p><\/div>\n

Hey presto, “get mail” retrieved the message I’d created while testing at the command line. With the configuration above, I was even able to send more messages to myself.<\/p>\n

Looking at this, it became obvious where the emails were being stored: \/var\/mail\/rob. A quick look there and I found a text file containing all my emails.<\/p>\n

Next step was to create an anonymous alias that I could use in my rails code. To do this I updated my etc\/aliases file by adding this to the end:<\/p>\n

developer: rob<\/div><\/div>\n

At first this had no effect. I then found this article by Elliot Smith<\/a>, which told me what I was missing:<\/p>\n

sudo newaliases<\/div><\/div>\n

That command regenerates your alias database file. As soon as I did that, I found I was able to send emails to developer@localhost.<\/p>\n

Last but not least I needed to set up my rails app to work with this configuration. I added this to \/config\/environments\/development.rb:<\/p>\n

  config.action_mailer<\/span>.smtp_settings<\/span> = {<\/span>
\n    :address<\/span>              =><\/span> "localhost"<\/span>,
\n    :port<\/span>                 =><\/span> 25<\/span>,
\n    :domain<\/span>               =><\/span> 'localhost'<\/span>,
\n    :authentication<\/span>       =><\/span> 'none'<\/span>,
\n    :openssl_verify_mode<\/span> =><\/span> 'none'<\/span>
\n  }<\/span><\/div><\/div>\n

And added this to the end of that file<\/p>\n

class<\/span> OverrideMailReciptient
\n  def<\/span> self<\/span>.delivering_email<\/span>(<\/span>mail)<\/span>
\n    mail.to<\/span> = "developer@localhost"<\/span>
\n  end<\/span>
\nend<\/span>
\nActionMailer::Base<\/span>.register_interceptor<\/span>(<\/span>OverrideMailReciptient)<\/span><\/div><\/div>\n

Overriding the mail recipient causes all emails leaving your rails app, to be redirected to the given address. With that in place, I could play with things like devise sign up confirmation emails without anything leaving my virtual environment. Just what I wanted.<\/p>\n

It was all so simple, I don’t really know why I haven’t done this before.<\/p>\n

Update: Catching all emails<\/strong>
\nI’ve needed to update my settings so that I can send an email to any email address, and it will end up in the rob@localhost mailbox. To do this, I followed the instructions given here<\/a>.<\/p>\n

I created \/etc\/postfix\/virtual :<\/p>\n

\/.*\/  rob@localhost<\/div><\/div>\n

I then added this to the bottom of etc\/postfix\/main.cf :<\/p>\n

# Set up rob@localhost to catch mail not directed to a specfic email address
\nvirtual_alias_maps = regexp:\/etc\/postfix\/virtual
\nvirtual_alias_domains =<\/div><\/div>\n

I then ran these two commands to create the mapping and restart postfix:<\/p>\n

sudo postmap \/etc\/postfix\/virtual
\nsudo postfix reload<\/div><\/div>\n

Now all emails sent to localhost:25 end up in the rob@localhost mailbox.<\/p>\n","protected":false},"excerpt":{"rendered":"

I’m working on an application that needs to send notifications via email, and I want to be able to test it in the development environment. In the past, I’ve either been able to set up a small Windows mail server … Continue reading →<\/span><\/a><\/p>\n","protected":false},"author":3,"featured_media":0,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":[],"categories":[3],"tags":[],"_links":{"self":[{"href":"http:\/\/nicholshayes.co.uk\/blog\/index.php?rest_route=\/wp\/v2\/posts\/316"}],"collection":[{"href":"http:\/\/nicholshayes.co.uk\/blog\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/nicholshayes.co.uk\/blog\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/nicholshayes.co.uk\/blog\/index.php?rest_route=\/wp\/v2\/users\/3"}],"replies":[{"embeddable":true,"href":"http:\/\/nicholshayes.co.uk\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=316"}],"version-history":[{"count":15,"href":"http:\/\/nicholshayes.co.uk\/blog\/index.php?rest_route=\/wp\/v2\/posts\/316\/revisions"}],"predecessor-version":[{"id":525,"href":"http:\/\/nicholshayes.co.uk\/blog\/index.php?rest_route=\/wp\/v2\/posts\/316\/revisions\/525"}],"wp:attachment":[{"href":"http:\/\/nicholshayes.co.uk\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=316"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/nicholshayes.co.uk\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=316"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/nicholshayes.co.uk\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=316"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}