Add openssl verify mode and email encryption for smtp configuration (#3885)

* Add openssl verify mode and email encryption for smtp configuration
* Add spec for code coverage

db/migrate/20220116103902_add_open_ssl_verify_mode_to_channel_email.rb

@@ -0,0 +1,8 @@
+class AddOpenSslVerifyModeToChannelEmail < ActiveRecord::Migration[6.1]
+  def change
+    change_table :channel_email, bulk: true do |t|
+      t.string :smtp_openssl_verify_mode, default: 'none'
+      t.boolean :smtp_enable_ssl_tls, default: false
+    end
+  end
+end