Updated SMTP configuration (markdown)

SMTP-configuration.md

@@ -90,6 +90,7 @@ Also see: https://web.archive.org/web/20210925161633/https://webewizard.com/2019
   SMTP_EXPLICIT_TLS=false
   SMTP_USERNAME=<mail-address>
   SMTP_PASSWORD=<password>
+  SMTP_AUTH_MECHANISM="Login"
 ```
 
 ### Sendgrid
@@ -116,3 +117,16 @@ Full SSL:
   SMTP_PASSWORD=<full-api-key>
   SMTP_AUTH_MECHANISM="Login"
 ```
+
+## Passwords with special characters
+
+If you want to use some special characters within your password, it could be that you need to escape some of these characters to not confuse the environment variable parsers.<br>
+For example a `\` or `'` or `"` can be used, but sometimes they need to be escaped so that they actually used.
+It is probably best, if you use special characters, to always uses single quotes around the password.<br>
+Lets take the following password as an example: `~^",a.%\,'}b&@|/c!1(#}`<br>
+Here are a few characters which could break the environment variable parses like, `\`, `'` and `"`.
+A single `\` is normally used to escape other characters, so if you want to use a single `\`, you need to type `\\`.<br>
+Also, the quotes `'` and `"` could cause some issues, so lets enclose this password within single quotes and escape the special characters.<br>
+To have the password above to work we need to type `'~^",a.%\\,\'}b&@|/c!1(#}'`, here you see that we escaped both the `\` and the `'` characters and used single quotes to surround the whole password.
+So: `~^",a.%\,'}b&@|/c!1(#}` becomes `'~^",a.%\\,\'}b&@|/c!1(#}'`
+