Main email address for "Contact Us" in settings is not changing
If you are using the popular 'Contact Form' plugin, try Settings &gt; Contact Form (under Plugins heading) and the field you want is the first field, 'To Email'.
The variables in Globals are 100% custom but usually change the email address that is displayed sitewide such as in your footer or contact page. They can be, but are not necessarily, wired into your contact form.
If you can't see Settings in the left side nav, or the Plugins section in Settings, you may need to request greater permissions from your CMS admin.
Be gentle (mods), this is my first answer in a long time ;)