Updated readme

README.md

@@ -1,2 +1,31 @@
 # blacklist_check
-Check your email server via bash if you are blacklisted
+Check your email server with bash using several RBL (Realtime Blacklists) to see if you are blacklisted or not.
+
+Originally from https://www.saotn.org/bash-check-ip-address-blacklist-status/ with some changes.
+
+# Usage
+
+```
+git clone https://github.com/TECH-SAVIOURS-ORG/blacklist_check.git
+cd blacklist_check
+chmod u+x blacklist_check.sh multi_server.sh
+```
+
+## One server:
+```
+./blacklist_check.sh IP
+```
+
+## Multiple server:
+Add your email server to the list. Each server per line.
+
+```
+nano email_server.txt
+```
+```
+email_server.com
+second.email_server.com
+```
+```
+./multi_check.sh
+```