What type of Pull Request is this?

• Update of existing guides
• Fix
• Optimization

Description

Fix product availability in CA/US locale guides — email & Exchange

Removes references to products not available in the CA/US region from 23 locale files across 7 guides:

• Email Pro removed from email_owa, how_to_configure_outlook_2016, faq-emails (objective, requirements, cross-links)
• Private Exchange removed from how_to_configure_thunderbird, how_to_configure_thunderbird_mac, manage_billing_exchange (requirements, "Go further" links, full billing section) and diagnostic_retention (webmail tip callout)
• CP-NAV templates (web-exchange) added to how_to_configure_thunderbird and how_to_configure_thunderbird_mac CA/US locales
• EU locales are unchanged. APAC locales were verified clean (no action needed).