Update sSMTP README

ssmtp_conf-sample/README.md

@@ -4,7 +4,7 @@ Once you have installed sSMTP on your Linux system, make sure the following appl
 
 ----------
 
-**1)** Create symbolic link from `/usr/bin/ssmtp` to `/usr/bin/sendmail` exists:
+**1)** Check that symbolic link from `/usr/bin/ssmtp` to `/usr/bin/sendmail` exists:
 
 ```
 ln -s /usr/bin/ssmtp /usr/bin/sendmail
@@ -64,15 +64,16 @@ Configure your message defined in [wanchecker.sh](wanchecker.sh) file.
 
 |     Variable     |                                    Value                                    |    Type    |
 |------------------|-----------------------------------------------------------------------------|------------|
-| EMAIL_SENDER     | Sender's address                                                            | String     |
-| EMAIL_RECIPIENTS | Email recipients. Multiple allowed                                          | Bash array |
 | SUBJECT_EMAIL    | Email title                                                                 | String     |
 | MESSAGE_EMAIL    | Email message contents                                                      | String     |
 | MESSAGE_STDOUT   | Internal Linux system message about sent email message                      | String     |
 | WANIP_DIR        | Log file directory path. User `mail` must have write access to this folder. | String     |
 | WANIP_LOG        | Log file name                                                               | String     |
 
-**NOTE:** At minimum, you should configure proper email addresses in variables `EMAIL_SENDER` and `EMAIL_RECIPIENTS`. `EMAIL_SENDER` takes same value as defined in `/etc/ssmtp/ssmtp.conf` ([sample](ssmtp.conf)) and `/etc/ssmtp/revaliases` ([sample](revaliases)) files.
+## Mail sender and recipients
+
+These are found in `/etc/ssmtp/wanchecker.conf` which is a bash `source` file.
+The conf file has three variables: `ENABLE_FALLBACK_DNS`, `EMAIL_SENDER` and `EMAIL_RECIPIENTS` which **must be** configured. `EMAIL_SENDER` takes same value as defined in `/etc/ssmtp/ssmtp.conf` ([sample](ssmtp.conf)) and `/etc/ssmtp/revaliases` ([sample](revaliases)) files.
 
 ## Folder & file permissions
 
@@ -92,6 +93,7 @@ Contents of `/etc/ssmtp/` folder should contain the following files & permission
     -rw-r----- 640 root:mail /etc/ssmtp/revaliases
     -rw-r----- 640 root:mail /etc/ssmtp/ssmtp.conf
     -rwxr-x--- 750 root:mail /etc/ssmtp/wanchecker.sh
+    -rwxr-x--- 640 root:mail /etc/ssmtp/wanchecker.conf
 ```
 
 **NOTE:** As `/etc/ssmtp/ssmtp.conf` contains a _clear-text email password_, the file must be protected from any eavesdropping with correct permission policy! The file must not be readable to any other than `mail` user, and `mail` user must not be available for normal usage. Still, any `sudo` group member can access the file, so make sure `sudo` group does not contain hostile or unwanted members, and configure your `/etc/sudoers` file properly.