I use BCC to Dropbox with pretty much every email I send to an external contact. What I have discovered is that the email I sent sometimes shows up in the contact's record and sometimes it doesn't.

I can see no reason for this and I do not believe it is 'operator error'. 

I used to trust Zoho implicitly to do this and then discovered that it doesn't so now I don't trust the system.

I did notice once in my Setup that Zoho had changed the Search Pattern rule about adding new contacts when I used the BCC to Dropbox without my knowledge! This has prompted me to keep checking.

I understand that I can regenerate my BCC email address, however I would like to know where the emails have gone and why this is happening. 

Very disappointing! 

Thanks