Why was heirloom-mailx deleted from Ubuntu 18.04?

It broke my mail agent, since I need to redirect to an external smtp server, and nothing else seems to do that properly.

Solution 1:

heirloom-mailx is a transitional (meaning "dummy" package that could go away at any time) package that was included in the s-nail source package.

Starting with s-nail version 14.9.4-1 in Debian, they removed the heirloom-mailx package as it was a transitional package. All it did was pull in s-nail and then set up a symlink of heirloom-mailx to s-nail's binaries.

The changelog for this is here (from http://metadata.ftp-master.debian.org/changelogs/main/s/s-nail/unstable_changelog):

s-nail (14.9.4-1) unstable; urgency=medium

  * New upstream version 14.9.4
  * Modernize package: DH compat level, Vcs-* URL, Standards-Version
  * Remove heirloom-mailx transitional package (Closes: #876871)
  * Drop patch
  * Simplify debian/rules: Fix parameter setting, use tmp $HOME for tests

 -- Hilko Bengen <[email protected]>  Sun, 01 Oct 2017 11:17:41 +0200

The Debian bug for this was Debian Bug #876871 about a non-empty transitional package - transitional packages are supposed to be 'dummy' packages which contain nothing but dependencies on other packages, but in this case it just contained a symlink for compatibility (and was not a valid 'transitional package' per Debian policy).

It looks like the Debian maintainer removed the package since it's not a transitional package. You should adapt your mail agent (if possible) to use the proper executable rather than the heirloom-mailx which only was a symlink to an actual executable. Failing that, you should consider looking for a new replacement MTA.

Solution 2:

heirloom-mailx was a transitional package whose only purpose was to pull in s-nail. The latter is still available in bionic and newer.

https://packages.ubuntu.com/artful/heirloom-mailx