If your network and firewall aren’t blocking email ports – SMTP (25), POP3 (110 and 995), and IMAP (143 and 993) – it’s likely your VPN restricting your ability to send emails via Outlook, Thunderbird, Apple Mail, etc. There are no issues receiving email in your email app or sending email in Webmail. You can do everything else on the internet. You’re trying to clean up your inbox but your email responses don’t send – they sit in your outbox. You’re at home or in your favorite lounge with your virtual private network (VPN) application enabled because you’re connected to an open public network.
Many privacy-conscious users have been there.