で送ってください

please send by

→ で
phrase Rare #24,049
please send by The particle で indicates the method or means of sending, such as by sea mail, express mail, air mail, or as an attachment. ください makes the request polite.
JA: この住所にメールで送ってください。
EN: Please send it to this address by email.

その本を郵便で送ってください

Please send that book by mail.

これをフェデラル・エクスプレスで送ってください

Please send this by FedEx.

速達で送ってください

Please send it by express mail.

手紙を速達で送ってください

Please send the letter by express mail.

それを航空便で送ってください

Please send it by airmail.