Texte d'origine - Anglais - I would like to say thank you very much.

Hello 亜美流,
What are you thanking this person/these people for, and when did the event happen? Is it still going on? (For example, is it a regular or continuing gift, or is it just one event in the past?)
The reason why I ask is because the Japanese way of expressing your gratitude is different for different sorts of kindnesses, and the tense is different (past/present) if it was a once-only past event, or an ongoing kindness.