Wondering if there's a way to specify that all e-mails to a specific contact should be sent as plain text ?

I know the option to reply with same format or to send all e-mail as plain text exist but we're having an issue with one of our contacts being unable to print our e-mails and sending it as plain text to him would fix that issue. However, we'd like to retain HTML messages for everyone else without the user having to change the text body type every time we send him a new e-mail.

Is there an option to do this somewhere ?