We recently heard from a client concerned that a few of his customers weren't receiving automated emails. His email account was filling with hundreds of bounce notifications, customers were getting frustrated, and there was nothing he could do about it.
Inspection of the Postfix logs on his and several other servers revealed a systematic problem. When these apps were first deployed, most emails were successfully delivered to customers (although a few might have ended up in the Spam/Bulk folder). Over the years, however, the spam problem has only gotten worse; and email clients, ISPs, and mail services aggressively terminate suspect messages with extreme prejudice.
Postfixer is a standalone utility powered by Capistrano. Git clone it, drop in a config file, and say goodbye to the Spam folder.
$ git clone https://github.com/sumbach/postfixer.git $ cd postfixer $ cp config-hostname.example.com.yml config-errbit.thinkrelevance.com.yml
Here's a sample config:
# # config-errbit.thinkrelevance.com.yml # canonical_hostname: errbit.thinkrelevance.com additional_hostnames: - utility.thinkrelevance.com email_domains: - thinkrelevance.com forwarding_address: email@example.com envelope_sender: firstname.lastname@example.org application_user: deploy sudo_user: deploy address: errbit.thinkrelevance.com
Let's break it down:
canonical_hostname: Fully-qualified domain name (FQDN) for your application server
additional_hostnames: Any additional hostnames that this server is known by (may be empty)
email_domains: All domains for which this server should be able to send email
forwarding_address: Email address for local messages (such as errors from cron jobs)
envelope_sender: SMTP envelope sender (where bounce messages end up)
application_user: Local user account under which your application runs
sudo_user: Local user account with root sudo permissions
address: FQDN or IP address used to SSH into this server
Once you've updated your Postfixer config, a number of cap tasks are at your disposal:
$ export CONFIG=errbit.thinkrelevance.com # specifies which .yml file Postfixer uses $ cap email:send_test_email # send a test message $ cap email:check_dns # print a report of your existing DNS entries
The send_test_email task uses the very helpful port25 verifier. If you're like me, the response to the test email looks something like this:
========================================================== Summary of Results ========================================================== SPF check: softfail (BAD) DomainKeys check: neutral (BAD) DKIM check: neutral (BAD) Sender-ID check: softfail (BAD) SpamAssassin check: ham (GOOD)
Yuck! Let's fix that up.
$ cap email:install_packages # install DKIM-milter (and Postfix, if not installed) $ cap email:backup_config # archive your current config files $ cap email:generate_config # generate new config file based on the .yml $ cap email:install_config # copy new config files to the server $ cap email:restart # restart Postfix and DKIM-milter $ cap email:print_dns # generate a report of the DNS changes you should make
Based on the output from print_dns, you should add/update your DNS configuration. If you're using Slicehost for DNS, log in and edit DNS entries via SliceManager. Otherwise, check with your registrar (Namecheap, GoDaddy, etc).
(Note: print_dns assumes you're using Google Apps. If you're using your ISP's or your own incoming mail server, replace "include:_spf.google.com" in the SPF records with something appropriate to your setup.)
Once you've updated your Postfix config and DNS entries, give
cap email:send_test_email another try.
========================================================== Summary of Results ========================================================== SPF check: pass (GOOD) DomainKeys check: neutral (BAD) DKIM check: pass (GOOD) Sender-ID check: pass (GOOD) SpamAssassin check: ham (GOOD)
Ahhhhh, much better.
Postfixer does not (yet) check if your server is on a blacklist
Postfixer does not check for general DNS issues
Posfixer does not (yet) support Yahoo DomainKeys (as seen in the port25 verifier results above)
Huge thanks to Relevance for giving me Fridays to make these kinds of contributions.
Thanks also to Shay Frendt for being my first guinea pig and for his new feature ideas.
That sounds great; I'd like you to contribute, too! Postfixer is available on Github and distributed under the MIT license.