Possible Clues:

• Also addresses, as with an e-mail
• Adds to a missive
• Syringe measurements: abbr.
• Brings into the conversation, in a way
• E.R. amts.
• Units in an ER
• IV dosage units
• Includes indirectly, in a way
• Also sends to, as an e-mail
• Sends the same e-mail to