libmailtransport4 software package provides mail transport service library, you can install in your Ubuntu 14.04 LTS (Trusty Tahr) by running the commands given below on the terminal,
$ sudo apt-get update $ sudo apt-get install libmailtransport4
libmailtransport4 is installed in your system.
Make ensure the libmailtransport4 package were installed using the commands given below,
$ sudo dpkg-query -l | grep libmailtransport4 *
You will get with libmailtransport4 package name, version, architecture and description in a table
| Distro | Ubuntu 14 04 lts trusty tahr |
| Section | Libraries |
| Package | libmailtransport4 |
| Version | 4:4.13.3-0ubuntu0.3 [amd64, i3 |
| Description | mail transport service library |
| Sub Section | libs |