Email Client Configuration

Your Opalstack email service includes IMAP, POP3, and SMTP servers to let you work with your email. These servers can be used to receive and send email with with desktop and mobile email clients, web applications, programming languages, or any other tool that uses these common mail protocols.

Email client settings are outlined below. Note that before you can configure your email client settings, you must first create a mail user and an email address.

Incoming Mail (IMAP)

  • Server hostname:
    • United States: mail.us.opalstack.com
    • Germany: mail.de.opalstack.com
  • Username: your mail user's name
  • Password: your mail user's password
  • Authentication type: Normal password (some clients show this as just "Password")
  • Secure port - SSL: 993

Incoming Mail (POP3)

  • Server hostname:
    • United States: mail.us.opalstack.com
    • Germany: mail.de.opalstack.com
  • Username: your mail user's name
  • Password: your mail user's password
  • Authentication type: Normal password (some clients show this as just "Password")
  • Secure port - SSL: 995

Outgoing Mail (SMTP)

  • Server hostname:
    • United States: smtp.us.opalstack.com
    • Germany: smtp.de.opalstack.com
  • Username: your mail user's name
  • Password: your mail user's password
  • Authentication type: Normal password (some clients show this as just "Password")
  • Secure port - SSL: 465
  • Secure port - TLS: 587
  • Sender address: domain must meet the requirements detailed in Outgoing Mail Domains