oversend
To send an amount greater than what is required; to oversupply.
Yes; and unfortunately sometimes we overorder, and sometimes they oversend, and much of it is thrown away.
To send (a message, etc.) to too many people.
Don't oversend. That means don't send an e-mail announcement to everyone who may have once sent you an e-mail; it also means don't overburden those who are willingly on your e-mail list because they want relevant information. Oversending e-mails is the surest way to be ignored or find your way to the junk mail file.
To send over, transmit.
DEAR SIR I do hereby oversend you my memorandum for fall goods and an other from Dr. C. Miller for Medicine.
Where it comes from
From Middle English oversenden (“to send over, transmit”), from Old English ofersendan (“to transmit”), from Proto-Germanic *uber (“over”) + *sandijaną (“to send”), corresponding to over- + send. Cognate with Middle Dutch oversenden (“to send over”), German übersenden (“to send, transmit”).
Adapted from the Wiktionary entry oversend (CC BY-SA 4.0).