Can't Delete Cached Email Addresses
 

So not to keep derailing the other thread, I see Blackberry is aware of the issue with no fix in place. It was recommended on Crackberry to delete the account, reboot the phone (Vol. Up/Down), and then add back the email account. Kind of a long drastic measure since I have eight email accounts in my phone. Still wondering about doing the security wipe (which will clear all) and then restoring everything but email accounts but again that's just nuts.

KB34279-Unable to clear the recent contact suggestions that are displayed when composing an email on the BlackBerry 10 smartphone

Re: Can't Delete Cached Email Addresses
 

Your trying to avoid seeing the suggestions offered when you want to create a new email? why? just ignore them and add what you want.
Some developer at Blackberry thought it would help and probably was trying to be cool.

Re: Can't Delete Cached Email Addresses
 

Not cool to me. I think the developers don't think it through sometimes. That cache file will continue to increase in size. MS Outlook has the same thing but you can purge that file or even delete each email one by one within Outlook. I just want the emails to show from within my contacts (not every email ever received which includes spam addresses). For some it may be OK, I just find it to be annoying.