Hi FR-Tech!
Here is the last ad-hoc request for a non-English MC Upsell Thank you email (i.e. "I had to email you twice..."). The rest of the 20ish languages I will do in one big batch in Q2. However, since the French campaign is in Q1 and coming up, we have done an ad-hoc job.
Please see here the French translation for this TY email.