International Business Etiquette or to -san or not to -san

[CU Tiger]

Long story short.,.
Involved in a pretty big negotiation for my company. The potential client's parent company is Japanese. Had a meeting Friday to discuss the technical aspects of my proposal. Surprisingly to me, in addition to the contact I have been working with one of the owner's parent company's reps was in attendance.

Things are looking very good for my company. So much so that over the weekend the Japanese rep sent me 3 additional emails asking for very minute qualifications. In each of those emails he addressed me as Cu Tiger-san.

It is time to reply.
I see three options:
A) Ignore the honorific suffix for fear it will come across as pandering or fake since it is not native to American culture
B) Reply xxx-san in kind
C) More proper reply XXX-sama in a show of respect for their business potential.

What say, ye oh Great FOFC group think?

[CraigSca]

When working with our Japanese partners, we always added the -san. I don't think it was pandering, more out of respect for their culture.

[digamma]

Whatever you do, don't google xxx-san.

[SirFozzie]

digamma... are you saying it gave you a -SANity loss>?

(grin, duck, hobble away)

[Bisbo]

Definitely use -san. You can never be too polite in any kind of a formal setting.

[wustin]

Unless they have gigantic leverage over your company, don't use -sama.