Please consult FAQs below for an introduction on the subject.

POST is phasing out the usage of unencrypted and unauthenticated connection methods to our platforms.
If you have been referred to this page, please review the connectivity guide below that most closely represents your use case.
Both your POP3/IMAP and SMTP configurations should use an encrypted connection (SSL/TLS) and username/password.

Configuration & Modification of most common email clients:

• Generic Email Client Configuration ( applies for most email clients)
• Microsoft Outlook email client configuration
  • Windows Outlook
  • Apple Mac Outlook
• Apple Mac Mail
• Apple iPhone email client configuration
  • Mail email client
  • Outlook email client
• Android email client configuration
  • Samsung Email configuration
  • Gmail Client configuration (applies to many Android based smartphones)

FAQ

Encrypted Email Client Configuration – Introduction.

What is an email client ?

Why should IMAP be preferred over POP ?