Mail Autoconfig

A ruby gem to detect and parse any Thunderbird autoconfig file for a domain. Includes a copy of the Mozilla ISPDB.

For general information about autoconf visit (, for the autoconfig schema you should have a look at (

Although I've tried to keep parsing as accurate as possible, there may be omissions or errors. Please feel free to submit a patch in these cases.


Add this line to your application's Gemfile:

gem 'mail_autoconfig'

And then execute:

$ bundle

Or install it yourself as:

$ gem install mail_autoconfig


Generally, you just want to get any associated configuration for an email address. In this case we'll use ''.

client_config = MailAutoconfig::for_address('')
=> "GMail"
outbound_server = client_config.outgoing_servers.first
=> "smtp"
=> ""

When searching for a configuration, autoconfig first looks to it's local database for the domain of the address, if this fails it will check http://autoconfig.#{domain}/mail/config-v1.1.xml and then http://#{domain}/.well-known/autoconfig/mail/config-v1.1.xml. If both of these fail, Autoconfig will then look up the MX records for the address, and perform the same searches on the domain of the primary MX record.

Updating the database

You may wish to update the database at some point to fetch the latest from Mozilla's ISPDB, just run the rake task rake fetch_ispdb.


  1. Fork it ( )
  2. Create your feature branch (git checkout -b my-new-feature)
  3. Run the test suite, check out haven't broken anything (bundle exec rspec spec)
  4. Commit your changes (git commit -am 'Add some feature')
  5. Push to the branch (git push origin my-new-feature)
  6. Create new Pull Request