16

This also worked:

https://productforums.google.com/forum/#!topic/gmail/NGVMo2it394

Users of Eudora affected by new SSL certificates
by wmadavis Mar 26

Users of the beloved orphaned email client Eudora 7.1 (and before) who download their POP Gmail are being affected by what seems to be Google rolling out new SSL certificates. The fix appears to be to designate the certificate as trusted, and these instructions have worked for me and for a friend:

  1. Launch Eudora from a closed state (or close it and then open it)
  2. Check Email
  3. Get error message “the server’s SSL Certificate was rejected for the following reasons…” Click YES (multiple times if needed)
    ---- You need the error message for the later steps to work.
  4. Click on TOOLS → PERSONALITIES
  5. Right-click on DOMINANT personality → PROPERTIES (or right-click on the affected personality)
  6. Click on INCOMING MAIL tab (when downloading is the problem)
  7. Click on LAST SSL INFO button
    ---- IF you get an error message saying “you have never done any SS negotiation…” then go back to step 1
  8. Click on CERTIFICATE INFORMATION MANAGER
  9. Under SERVER CERTIFICATES, click on the [+] sign inside the little box to open up the item below, and keep opening additional + signs until you get to the bottom.
    ---- the bottom one should have a skull icon (untrusted)
  10. Click on the bottom item (skull) to highlight it and then click on the ADD TO TRUSTED button.
  11. Click DONE, OK and close everything out.