I'm missing the ssmtp package in debian jessie alpha 1 (extremely simple MTA to get mail off the system to a mail hub). It's available in wheezy and sid.
Has this package been discontinued? What are the alternatives?
In general to figure out why a package has been removed from testing (and lots of other stuff), you can go to https://packages.qa.debian.org and type in the source package name. In this case, you go to https://packages.qa.debian.org/s/ssmtp.html.
Going to news, you see the link ssmtp REMOVED from testing, which references Debian bug 584162: Partial loss of message body, sending message to wrong recipicients. However, it is still available in Debian unstable. To see the exact versions available, ou can run
apt-cache policy, assuming you have the necessary sources available.
ssmtp: Installed: (none) Candidate: 2.64-7 Version table: 2.64-7.1 0 50 http://debian.lcs.mit.edu/debian/ unstable/main amd64 Packages 2.64-7 0 500 http://debian.lcs.mit.edu/debian/ wheezy/main amd64 Packages
if you are not familar with how Debian works, a package may be removed from testing (which will become the next release), if it has a sufficiently serious bug open against it for sufficiently long. The exact rules change - I don't know what the current rules are. However, in such cases, the package continues to be available in unstable.
From the bug report, it looks like there is a patch against this bug, and that it will be fixed. However, in the meantime, this package has been removed from testing, probably by automatically run scripts. Looking at the changelog, it looks like this bug has not been fixed by the version in unstable.
Suggestion: use the version in unstable
apt-get install ssmtp/unstable
unless you are concerned by the bug in question, in which you could patch the package yourself, or wait for the fix. Querying the bug report about when the fix will arrive in unstable is also an option. You'd have to email the bug report address, 584162 at bugs.debian.org, and possibly also the other people CCed.