Fix Sendmail configuration

CHANGELOG.md

@@ -8,6 +8,13 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 
 ### v3.9.x - [Unreleased]
 
+### v3.12.4 - 2020-10-14
+
+#### Fixed
+
+- Avif (AV1 Image Format) & WebP Nginx conditional support([PR #322](https://github.com/WordOps/WordOps/pull/322))
+- Sendmail initial configuration with sendmailconfig
+
 ### v3.12.3 - 2020-10-13
 
 #### Added

wo/cli/plugins/stack_pref.py

@@ -1135,6 +1135,16 @@ def post_pref(self, apt_packages, packages, upgrade=False):
                 WOGit.add(self, ["/etc/proftpd"],
                           msg="Adding ProFTPd into Git")
 
+        # Sendmail configuration
+        if "sendmail" in apt_packages:
+            if (os.path.exists("/usr/bin/yes") and
+                    os.path.exists("/usr/sbin/sendmailconfig")):
+                Log.wait(self, "Configuring Sendmail")
+                if WOShellExec.cmd_exec(self, "yes 'y' | sendmailconfig"):
+                    Log.valide(self, "Configuring Sendmail")
+                else:
+                    Log.failed(self, "Configuring Sendmail")
+
         if "ufw" in apt_packages:
             # check if ufw is already enabled
             if not WOFileUtils.grep(self,