Hello
I have a Ubuntu SMP command line distro, release 4.15.0-132-generic and I'm having trouble setting up the webmail for it. I've done sudo apt-get update and then sudo apt-get install ssmpt and the error I receive is 'Package ssmtp is not available, but is referred to by another package. This may mean that the package is missing, has been obsoleted, or is only available from another source'. I then tried to use mutt, which installed successfully, but when I typed in mutt -s "test" myemail(at)gmail.com < /dev/null, I received the error 'Error sending message, child exited 127 (Exec error.). Could not send the message.' Ok, so maybe mutt isn't configured (and I need a new email domain?). Googling it, I got the advice to use
touch ~/.mutt/muttrc to setup mutt. Except using that, I received the error message 'No such file or directory'. In the end, all I care is that, at the end of the day, I end up with a working email from my Ubuntu SMP OS. Suggestions? Fixes? Thanks in advance.

You don't need ssmtp (or any MTA) in order to configure mutt to use GMail. There are plenty of info on this subject on the net.

Start with MuttWiki.

Also see How to install, configure, and use mutt with a gmail account on Linux at linuxconfig.org and Mutt+Gmail.

Thank you. Fixed most of my problems, but I'm still having issues sending anything. Tried without smpt, get exit child error 127. Configed with smpt and gmail with the recommendations on all the links, keep getting invalid SMPT URL error despite changing syntax. Made sure sendmail was installed, etc, despite creating a .config file and making sure installed, I also get a cannot open mail:25 error. Not sure if connected or not but in my research there was something about mutt using sendmail. Not sure where to go from here.

As shruggy has posted you need to configure your .muttrc file as shown in the links provided. You might need to configure your gmail account to accept connections from mutt with ouath2.
The default configuration file for mutt is ~/.muttrc

To send email from the command line using mutt
Where -s is the subject and the contents of your email is message.txt

I did that already. I STARTED with configuring the muttrc file as described in the posts, then went looking on the web for additional help when I got everything to work except the smpt configuration. Even tried taking that out of the file and several syntax variations. Was wondering if anyone else had that problem in there muttrc file and how they solved it if they did.

I get mail:25 error with the command you described. When I go into mutt, then y for send, I get smtp invalid error, despite using the recommended syntax.
I'm having a similar problem as the person in this post https://unix.stackexchange.com/quest...ng-smtp-server
Except the recommended fix (using my user name of course) doesn't fix the problem. Thanks.