Reset umask to 0022 at beginning of install

Fix: #178 leakage of public IP addresses in sent emails

Prevented escape shell

Some strings will escape and break the script, inserted fixes like single quotes ( ' ' ).

Update README.md

Replaced 933 for 993, the correct port for IMAP.

Fix: Opendkim won't start: can't open PID file?

Fix typo in LICENSE filename

Update emailwiz.sh

Make gmail's less angry

Update emailwiz.sh

Ubuntu can't run multiple lines without a special character, thus making the script malfunction, putting the commands on the same line solves the problem and the script can be used on Ubuntu 20.04

Fixes for custom subdomain names

Enforce TLS1.2 connections

Add extra troubleshooting points, minor readability changes

documentation changes

Make README clearer about PTR record

Fixed Tiny Grammar Error

Literally added one letter