French phrase
Je vous contacterai par ~ d'ici ~.
Meaning
I will contact you by ___ by ___.
When to use it
States a contact method and a deadline. Polite and businesslike, often used to promise a follow-up.
Example dialogue
Je vous contacterai par téléphone d'ici la fin de la journée.
I will contact you by phone by the end of the day.
D'accord, merci, je reste disponible.
Okay, thank you. I remain available.