Thanks to Fergus Duncan for these instructions

• Import Certificate as Described.
• Tools/Accounts - New Account or Edit Existing by Double-Clicking on Account
• General Tab, complete as appropriate:
  • Account Name
  • Name
  • Organisation
  • Email Address
  • Reply Address
• Servers Tab
  • Incomong - POP3
  • Incoming Mail - mail.employees.org
  • Outgoing Mail - mail.employees.org
  • Account Name : whatever
  • Password : whatever_else
  • UNTICK Log on using Secure Password Authentication
  • TICK My Server Requires Authentication
• Connection Tab
  • Whatever you require
• Secutiry Tab
  • Algorithm 3DES
• Advanced Tab
  • Outgoing mail (SMTP) 25
  • TICK This server requires a secure connection (SSL)
  • Incoming mail (POP3) 995
  • TICK This server requires a secure connection (SSL)
  • Server Timeouts whatever
  • Sending and Delivery options whatever