We have an HR colleague that sends us tickets for accounts & laptops on a regular basis.

on october 16th she sent us an email with subject "Laptop + account voor Wxxx Oxxxxxxxxx"
Yet that email was added in old ticket ##54148## "laptop + account voor Sxxxxx Txxxxxx"

our colleague replied her out of the ticket and she replied back, so the email on the 18th made sence.


But today we had the same 
She sent an email "account voor Axxx Pxxxxx"
And the mail was added to the ticket 54148 with subject "Laptop + account voor Sxxxxx Txxxxx"

Can we disable this that he only merges if the ticketnumber is explicitly mentioned in the subject?