added Inboxen and postal in mail services (#1073)

* added Inboxen and postal in mail services

* sort Inboxen and postal in mail services

* Fix Postal Formatting

README.md

@@ -262,6 +262,7 @@ _simple deployment of a mail server, e.g. for inexperienced or impatient admins.
 
   * [Citadel](http://www.citadel.org/) - Feature packed, easy, versatile, and powerful mail server, thanks to exclusive "rooms" based architecture. ([Source Code](http://code.citadel.org/?p=citadel.git;a=summary)) `GPLv3` `C`
   * [docker-mailserver](https://github.com/tomav/docker-mailserver) - A fullstack but simple mail server (smtp, imap, antispam, antivirus, etc.). Only configuration files, no SQL database. Keep it simple and versioned. Easy to deploy and upgrade. `MIT` `Docker`
+  * [Inboxen](https://inboxen.org) - Inboxen is a service that provides you with an infinite number of unique inboxes. ([Source Code](https://github.com/Inboxen/Inboxen)) `GPLv3` `Python`
   * [iRedMail](http://www.iredmail.org/) - Full-featured mail server solution based on Postfix and Dovecot. ([Source Code](https://bitbucket.org/zhb/iredmail/commits/)) `GPLv3` `Shell`
   * [Mailcow](https://mailcow.email/) - Mail server suite based on Dovecot, Postfix and other open source software, that provides a modern Web UI for administration. ([Source Code](https://github.com/andryyy/mailcow)) `GPLv2` `PHP`
   * [Mail-in-a-Box](https://mailinabox.email/) - Turns any Ubuntu server into a fully functional mail server with one command. ([Source Code](https://github.com/mail-in-a-box/mailinabox)) `CC0` `Shell`
@@ -301,9 +302,11 @@ _Mailing lists servers and mass mailing software - one message to many recipient
   * [MailyHerald](http://mailyherald.org/) - Self-hosted Mailchimp alternative that you can easily integrate with your site. Helps you send and manage your application mailings. It support email marketing and conducting the daily stream of notifications you send to your users. ([Source Code](https://github.com/Sology/maily_herald)) `LGPLv3` `Ruby`
   * [Mautic](https://www.mautic.org/) - Mautic is marketing automation software (email, social & more). ([Source Code](https://github.com/mautic/mautic)) `GPLv3` `PHP`
   * [phpList](https://phplist.org) - Newsletter and email marketing with advanced management of subscribers, bounces, and plugins. ([Source Code](https://github.com/phpList/)) `AGPLv3` `PHP`
+  * [postal](https://github.com/atech/postal) - A fully featured open source mail delivery platform for incoming & outgoing e-mail. `MIT` `Ruby`
   * [Schleuder](https://schleuder.nadir.org/) - A GPG-enabled mailing list manager with resending-capabilities. ([Source Code](https://0xacab.org/schleuder/schleuder/tree/master)) `GPLv3` `Ruby`
   * [Sympa](https://www.sympa.org/) - A mailing list manager. `GPLv2` `Perl`
 
+
 #### Webmail clients
 
   * [Cypht](http://cypht.org/index.html) - A feed reader for your email accounts. ([Source Code](https://github.com/jasonmunro/hm3)) `GPLv2` `PHP`