Refers to the person or entity that initiates a communication, such as a phone call, email, or data transmission. Common in technical and everyday contexts.
メールの発信者を確認してください。
Please check the sender of the email.
発信者番号を非通知に設定する。
Set the caller ID to private.
送信者 is the standard term for the sender of an email or digital message, while 発信者 more broadly covers anyone who originates a transmission, such as a phone caller.
caller ID; originator indication
caller ID number
originator requested alternate recipient
Compound of 発信 (transmission, sending) + 者 (person). The reading is standard on'yomi.