If one has kmail open and disables nepomuk (system settings > desktop search > untick nepomuk + apply) nothing bad happens. If one re-enables nepomuk while kmail is still open kmail will consume 100% cpu after some seconds and never stops. E-Mail indexing is enabled, file indexing as well. Reproducible: Always
Thank you for your report. Sorry for long time to answer it. Your report relates to a version of KMail that still uses Nepomuk and is unmaintained. Thus closing. I think 100% cpu issues are gone with Baloo or Akonadi Search (renamed Baloo for mail starting with KDEPIM 15.08). If you still see this issue with KDEPIM 4.14 or 15.08, please reopen the report. Thank you, Martin