How do I set up Vivaldi email account in a mail client?

In your desktop or mobile email client create a new IMAP, or POP3 mailbox account using the following settings:

To receive e-mails, choose one the servers, below (Incoming server):

  1. POP3: pop3.vivaldi.net,

    • Port: 110,

    • Authentication method: normal password,

    • Connection security: STARTTLS

  2. IMAP: imap.vivaldi.net,

    • Port: 143,

    • Authentication method: normal password,

    • Connection security: STARTTLS

…or, instead, one of the two, below:

  1. POP3s: pop3.vivaldi.net,

    • Port: 995,

    • Authentication method: normal password,

    • Connection security: SSL/TLS

  2. IMAPs: imap.vivaldi.net,

    • Port: 993,

    • Authentication method: normal password,

    • Connection security: SSL/TLS

To send e-mails, set the server, below (Outgoing server):

  1. SMTP: smtp.vivaldi.net,

    • Port: 587,

    • Authentication method: normal password,

    • Connection security: STARTTLS

https://help.vivaldi.com/article/vivaldi-net-and-its-webmail/